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ART001661319
|
oai_dc
|
Ductility and inelastic deformation demands of structures
|
Ductility and inelastic deformation demands of structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Cheikh Benazouz(National Center for Applied Research in Earthquake Engineering); Leblouba Moussa(High National School of Public Works); Zerzour Ali(High National School of Public Works)"
] |
Current seismic codes require from the seismically designed structures to be capable to withstand inelastic deformation. Many studies dealt with the development of different inelastic spectra with the aim to simplify the evaluation of inelastic deformation and performance of structures. Recently,the concept of inelastic spectra has been adopted in the global scheme of the performance-based seismic design through capacity-spectrum methods. In this paper, the median of the ductility demand ratio for 80 ground motions are presented for different levels of normalized yield strength, defined as the yield strength coefficient divided by the peak ground acceleration (PGA). The influence of the post-to-preyield stiffness ratio on the ductility demand is investigated. For fixed levels of normalized yield strength, the median ductility versus period plots demonstrated that they are independent of the earthquake magnitude and epicentral distance. Determined by regression analysis of the data, two design equations have been developed; one for the ductility demand as function of period, post-to-preyield stiffness ratio, and normalized yield strength, and the other for the inelastic deformation as function of period and peak ground acceleration valid for periods longer than 0.6 seconds. The equations are useful in estimating the ductility and inelastic deformation demands for structures in the preliminary design. It was found that the post-to-preyield stiffness has a negligible effect on the ductility factor if the yield strength coefficient is greater than the PGA of the design ground motion normalized by gravity.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001661317
|
oai_dc
|
Vulnerability curves of masonry constructions Algiers case study
|
Vulnerability curves of masonry constructions Algiers case study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. Djaalali(University M’Hamed Bouguara); M. Bensaibi(University Saad Dahleb); N. Bourahla(University Saad Dahleb); L. Davenne(University Paris Ouest)"
] |
This study deals with the assessment of low and mid rise multi-story buildings made of stone and /or brick, composite steel and masonry slabs from the sixties, known to be vulnerable to seismic hazard using the “vulnerability index” method based on buildings survey following Ain Temouchent (1999) and Boumerdes (2003) earthquakes, from where vulnerability curves are constructed using the translation method. The results obtained for the case study confirm what has been observed in situ.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001661321
|
oai_dc
|
Secondary resonances of a microresonator under AC-DC electrostatic and DC piezoelectric actuations
|
Secondary resonances of a microresonator under AC-DC electrostatic and DC piezoelectric actuations
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Zamanian(Kharazmi University); S.A.A. Hosseini(Kharazmi University)"
] |
This article studies the secondary resonances of a clamped-clamped microresonator under combined electrostatic and piezoelectric actuations. The electrostatic actuation is induced by applying the AC-DC voltage between the microbeam and the electrode plate that lies at the opposite side of the microbeam. The piezoelectric actuation is induced by applying the DC voltage between upper and lower sides of piezoelectric layer. It is assumed that the neutral axis of bending is stretched when the microbeam is deflected. The drift effect of piezoelectric layer (the phenomenon where there is a slow increase of the free strain after the application of a DC field) is neglected. The equations of motion are solved by using the multiple scale perturbation method. The system possesses a subharmonic resonance of order one-half and a superharmonic resonance of order two. It is shown that using the DC piezoelectric actuation, the sensitivity of AC-DC electrostatically actuated microresonator under subharmonic and superharmonic resonances may be tuned. In addition, it is shown that the tuning domain of the microbeam under combined electrostatic and piezoelectric actuations at subharmonic and superharmonic conditions is larger than the tuning domain of microbeam under only the electrostatic actuation.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001661325
|
oai_dc
|
Finite element dynamic analysis of laminated composite beams under moving loads
|
Finite element dynamic analysis of laminated composite beams under moving loads
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Volkan Kahya(Karadeniz Technical University)"
] |
This study presents dynamic analysis of laminated beams traversed by moving loads using a multilayered beam element based on the first-order shear deformation theory. The present element consists of N layers with different thickness and material property, and has (3N + 7) degrees of freedom corresponding three axial, four transversal, and 3N rotational displacements. Delamination and interfacial slip are not allowed. Comparisons with analytical and/or numerical results available in literature for some illustrative examples are made. Numerical results for natural frequencies, deflections and stresses of laminated beams are given to explain the effect of load speed, lamina layup, and boundary conditions.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001661323
|
oai_dc
|
Effect of the thickness on the mixed mode crack front fields
|
Effect of the thickness on the mixed mode crack front fields
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Shafique M.A. Khan(King Fahd University of Petroleum and Minerals)"
] |
Results pertaining to 3D investigations on the effect of the thickness on the stress fields at the crack front are presented. A 3D finite element analysis is performed using a modified single edgenotched tension specimen configuration, with an inclined crack to include mixed mode I-II. A technique to mesh the crack front (3D) with singular finite elements in ANSYS without using third party software is introduced and used in this study. The effect of the specimen thickness is explicitly investigated for six thicknesses ranging from 1 to 32 mm. In addition, three crack inclination angles, including pure Mode-I, are used to study the effect of mixed-mode I-II fracture. An attempt is made to correlate the extent of a particular stress state along the crack front to thickness. In addition, σzz /ν (σxx + σyy) contours at the crack front are presented as a useful means to analyze the stress state.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001661326
|
oai_dc
|
Construct OCR on mobile mechanic system for android wireless dynamics and structure stabilization
|
Construct OCR on mobile mechanic system for android wireless dynamics and structure stabilization
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bih-Yaw Shih(National Pingtung University of Education); Chen-Yuan Chen(National Pingtung University of Education); Wei-Lun Su(National Pingtung University of Education)"
] |
In today's online social structure, people with electronic devices or network have been closely related to whether any of the activities, work, school, etc., is related to electronic devices, intelligent robot, and network control. The best mobility and the first rich media of these products as smart phones, smart phones rise rapidly in recent years, high speed processing performance and high free way to install software, deeply loved by many business people. However, not only for smart phone business aspects of the use, but also can engage in education of the teachers or the students are learning a great help. This study construct OCR-assisted learning software written by the JAVA made, and the installation is provided by the Android mobile phone users.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001661320
|
oai_dc
|
A study on the behaviour of coupled shear walls
|
A study on the behaviour of coupled shear walls
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dipendu Bhunia(BITS Pilani); Vipul Prakash(IIT Roorkee); Ashok D. Pandey(IIT Roorkee)"
] |
An effective design technique for symmetrical coupled shear walls is presented. Proposed formulation including assumptions and steps with mathematical formulation has been elaborated to make the design technique. An example has been considered to validate the technique with the DRAIN-3DX (1993) and SAP V 10.0.5 (2000) nonlinear programs. Parametric study has also been considered to find out the limitations along with remedial action of this technique. On the other hand, nonlinear static analysis is considered to determine the response reduction factor of coupled shear walls. Finally, it has been concluded in this paper that the proposed design technique can be considered to design the coupled shear walls under seismic motion.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001713764
|
oai_dc
|
Lateral capacity of piles in layered soil: a simple approach
|
Lateral capacity of piles in layered soil: a simple approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bikash Mandal(Bengal Engineering and Science University); Rana Roy(Bengal Engineering and Science University); Sekhar Chandra Dutta(Indian Institute of Technology Bhubaneswar)"
] |
Appropriate assessment of lateral capacity of pile foundation is known to be a complex problem involving soil-structure interaction. Having reviewed the available methods in brief, relative paucity of simple and rational technique to evaluate lateral capacity of pile in layered soil is identified. In this context, two efficient approaches for the assessment of lateral capacity of short pile embedded in bilayer cohesive deposit is developed. It is presumed that the allowable lateral capacity of short pile is generally dictated by the permissible lateral displacement within which pile-soil system may be assumed to be elastic. The applicability of the scheme, depicted through illustration, is believed to be of ample help at least for practical purpose.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713768
|
oai_dc
|
Modified Tikhonov regularization in model updating for damage identification
|
Modified Tikhonov regularization in model updating for damage identification
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J. Wang(Beijing Jiaotong University); Q.S. Yang(Beijing Jiaotong University)"
] |
This paper presents a Modified Tikhonov Regularization (MTR) method in model updating for damage identification with model errors and measurement noise influences consideration. The identification equation based on sensitivity approach from the dynamic responses is ill-conditioned and is usually solved with regularization method. When the structural system contains model errors and measurement noise, the identified results from Tikhonov Regularization (TR) method often diverge after several iterations. In the MTR method, new side conditions with limits on the identification of physical parameters allow for the presence of model errors and ensure the physical meanings of the identified parameters. Chebyshev polynomial is applied to approximate the acceleration response for moderation of measurement noise. The identified physical parameter can converge to a relative correct direction. A three-dimensional unsymmetrical frame structure with different scenarios is studied to illustrate the proposed method. Results revealed show that the proposed method has superior performance than TR Method when there are both model errors and measurement noise in the structure system.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713822
|
oai_dc
|
Strength of biaxially loaded high strength reinforced concrete columns
|
Strength of biaxially loaded high strength reinforced concrete columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Cengiz Dundar(Cukurova University); Serkan Tokgoz(Mersin University)"
] |
An experimental research was conducted to investigate the strength of biaxially loaded short and slender reinforced concrete columns with high strength concrete. In the study, square and L-shaped section reinforced concrete columns were constructed and tested to obtain the load-deformation behaviour and strength of columns. The test results of column specimens were analysed with a theoretical method based on the fiber element technique. The theoretical ultimate strength capacities and the test results of column specimens have been compared and discussed in the paper. Besides this, observed failure mode and experimental and theoretical load-lateral deflection behaviour of the column specimens are presented.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713816
|
oai_dc
|
An integrate information technology model during earthquake dynamics
|
An integrate information technology model during earthquake dynamics
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chen-Yuan Chen(National Pingtung University of Education); Ying-Hsiu Chen(Yuanpei University); Shang-En Yu(Ming Chuan University); Yi-Wen Chen(National Pingtung University of Education); Chien-Chung Li(Natonal Taiwan University)"
] |
Applying Information Technology (IT) in practical engineering has become one of the most important issues in the past few decades, especially on internal solitary wave, intelligent robot interaction, artificial intelligence, fuzzy Lyapunov, tension leg platform (TLP), consumer and service quality. Other than affecting the traditional teaching mode or increasing the inter-relation with users, IT can also be connected with the current society by collecting the latest information from the internet. It is apparently a fashion-catching-up technology. Therefore, the learning of how to use IT facilities is becoming one of engineers’ skills nowadays. In addition to studying how well engineers learn to operate IT facilities and apply them into teaching, how engineers’ general capacity of information effects the results of learning IT are also discussed. This research introduces the “Combined TAM and TPB mode,” to understand the situation of engineers using IT facilities.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713803
|
oai_dc
|
Crack driving force prediction based on finite element analysis using standard models
|
Crack driving force prediction based on finite element analysis using standard models
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Josip Brnic(University of Rijeka); Goran Vukelic(University of Rijeka); Goran Turkalj(University of Rijeka)"
] |
Effect of different crack sizes on fracture criterion of some engineering materials was investigated in this work. Using finite element (FE) method coupled with a newly developed algorithm, Jintegral values for different crack sizes were obtained for single-edge notched bend (SENB) and compact type (CT) specimen. Specimens with initial a/W ratio from 0.25 to 0.75 varying in crack size in steps of 0.125 were investigated. Several different materials, like 20MnMoNi55, 42CrMo4 and 50CrMo4, usually used in engineering structure, were investigated. For one of mentioned materials, numerical results were compared with experimental and their compatibility is visible.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713830
|
oai_dc
|
Dynamic response of Euler-Bernoulli beams to resonant harmonic moving loads
|
Dynamic response of Euler-Bernoulli beams to resonant harmonic moving loads
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Giuseppe Piccardo(University of Genoa); Federica Tubino(University of Genoa)"
] |
The dynamic response of Euler-Bernoulli beams to resonant harmonic moving loads is analysed. The non-dimensional form of the motion equation of a beam crossed by a moving harmonic load is solved through a perturbation technique based on a two-scale temporal expansion, which permits a straightforward interpretation of the analytical solution. The dynamic response is expressed through a harmonic function slowly modulated in time, and the maximum dynamic response is identified with the maximum of the slow-varying amplitude. In case of ideal Euler-Bernoulli beams with elastic rotational springs at the support points, starting from analytical expressions for eigenfunctions, closed form solutions for the time-history of the dynamic response and for its maximum value are provided. Two dynamic factors are discussed: the Dynamic Amplification Factor, function of the non-dimensional speed parameter and of the structural damping ratio, and the Transition Deamplification Factor, function of the sole ratio between the two non-dimensional parameters. The influence of the involved parameters on the dynamic amplification is discussed within a general framework. The proposed procedure appears effective also in assessing the maximum response of real bridges characterized by numerically-estimated mode shapes, without requiring burdensome step-by-step dynamic analyses.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713809
|
oai_dc
|
A simplified design procedure for seismic retrofit of earthquake-damaged RC frames with viscous dampers
|
A simplified design procedure for seismic retrofit of earthquake-damaged RC frames with viscous dampers
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"D.G. Weng(Tongji University); C. Zhang(Tongji University); X.L. Lu(Tongji University); S. Zeng(Tongji University); S.M. Zhang(Tongji University)"
] |
The passive energy dissipation technology has been proven to be reliable and robust for recent practical applications. Various dampers or energy dissipation devices have been widely used in building structures for enhancing their performances during earthquakes, windstorm and other severe loading scenarios. This paper presents a simplified seismic design procedure for retrofitting earthquakedamaged frames with viscous dampers. With the scheme of designing the main frame and the supplemental viscous dampers respectively, the seismic analysis model of damped structure with viscous dampers and braces was studied. The specific analysis process was described and approach to parameter design of energy dissipation components was also proposed. The expected damping forces for damped frame were first obtained based on storey shear forces; and then they were optimized to meet different storey drift requirements. A retrofit project of a RC frame school building damaged in the 2008 Wenchuan earthquake was introduced as a case study. This building was retrofitted by using viscous dampers designed through the simplified design procedure proposed in this paper. Based on the case study, it is concluded that this simplified design procedure can be effectively used to make seismic retrofit design of earthquake-damaged RC frames with viscous dampers, so as to achieve structural performance objectives under different earthquake risk levels.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001713826
|
oai_dc
|
Influence of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines
|
Influence of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kaiming Bi(The University of Western Australia); Hong Hao(The University of Western Australia)"
] |
Previous major earthquakes revealed that most damage of the buried segmented pipelines occurs at the joints of the pipelines. It has been proven that the differential motions between the pipe segments are one of the primary reasons that results in the damage (Zerva et al. 1986, O’Roueke and Liu 1999). This paper studies the combined influences of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines. The heterogeneous soil deposits surrounding the pipelines are assumed resting on an elastic half-space (base rock). The spatially varying base rock motions are modelled by the filtered Tajimi-Kanai power spectral density function and an empirical coherency loss function. Local site amplification effect is derived based on the one-dimensional wave propagation theory by assuming the base rock motions consist of out-of-plane SH wave or combined in-plane P and SV waves propagating into the site with an assumed incident angle. The differential axial and lateral displacements between the pipeline segments are stochastically formulated in the frequency domain. The influences of ground motion spatial variations, local soil conditions, wave incident angle and stiffness of the joint are investigated in detail. Numerical results show that ground motion spatial variations and local soil conditions can significantly influence the differential displacements between the pipeline segments.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649261
|
oai_dc
|
Estimation of bridge displacement responses using FBG sensors and theoretical mode shapes
|
Estimation of bridge displacement responses using FBG sensors and theoretical mode shapes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"신수봉(인하대학교); Sun-Ung Lee(Inha University); Yuhee Kim(Inha University); 김남식(부산대학교)"
] |
Bridge vibration displacements have been directly measured by LVDTs (Linear Variable Differential Transformers) or laser equipment and have also been indirectly estimated by an algorithm of integrating measured acceleration. However, LVDT measurement cannot be applied for a bridge crossing over a river or channel and the laser technique cannot be applied when the weather condition is poor. Also, double integration of accelerations may cause serious numerical deviation if the initial condition or a regression process is not carefully controlled. This paper presents an algorithm of estimating bridge vibration displacements using vibration strains measured by FBG (Fiber Bragg Grating) sensors and theoretical mode shapes of a simply supported beam. Since theoretically defined mode shapes are applied,even high modes can be used regardless of the quality of the measured data. In the proposed algorithm, the number of theoretical modes is limited by the number of sensors used for a field test to prevent a mathematical rank deficiency from occurring in computing vibration displacements.89The proposed algorithm has been applied to various types of bridges and its efficacy has been verified. The closeness of the estimated vibration displacements to measured ones has been evaluated by computing the correlation coefficient and by comparing FRFs (Frequency Response Functions) and the maximum displacements.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649257
|
oai_dc
|
Active control of delaminated composite shells with piezoelectric sensor/actuator patches
|
Active control of delaminated composite shells with piezoelectric sensor/actuator patches
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Namita Nanda(Indian Institute of Technology Delhi); Y. Nath(Indian Institute of Technology Delhi)"
] |
Present study deals with the development of finite element based solution methodology to investigate active control of dynamic response of delaminated composite shells with piezoelectric sensors and actuators. The formulation is based on first order shear deformation theory and an eight-noded isoparametric element is used. A coupled piezoelectric-mechanical formulation is used in the development of the constitutive equations. For modeling the delamination, multipoint constraint algorithm is incorporated in the finite element code. A simple negative feedback control algorithm coupling the direct and converse piezoelectric effects is used to actively control the dynamic response of delaminated composite shells in a closed loop employing Newmark’s time integration scheme. The validity of the numerical model is demonstrated by comparing the present results with those available in the literature. A number of parametric studies such as the locations of sensor/actuator patches, delamination size and its location, radius of curvature to width ratio, shell types and loading conditions are carried out to understand their effect on the transient response of piezoceramic delaminated composite shells.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649254
|
oai_dc
|
An Extended Force Density Method for the form finding of cable systems with new forms
|
An Extended Force Density Method for the form finding of cable systems with new forms
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"P.G. Malerba(Politecnico di Milano); Politecnico di Milano(Studio Malerba); M. Quagliaroli(Politecnico di Milano)"
] |
The Force Density Method (FDM) is a well known and extremely versatile tool in form finding of cable nets. In its linear formulation such method makes it possible to find all the possible equilibrium configurations of a net of cables having a certain given connectivity and given boundary conditions on the nodes. Each singular configuration corresponds to an assumed force density distribution.
Its improvement as Non-Linear Force Density Method (NLFDM) introduces the possibility of imposing assigned relative distances among the nodes, the tensile level in the elements and/or their initial undeformed length. In this paper an Extended Force Density Method (EFDM) is proposed, which makes it possible to set conditions in terms of given fixed nodal reactions or, in other words, to fix the positions of a certain number of nodes and, at the same time, to impose the intensity of the reaction force. Through such extension, the (EFDM) enables us to deal with form findings problems of cable nets subjected to given constraints and, in particular, with mixed structures, made of cables and struts. The efficiency and the robustness of method are assessed through comparisons with other form finding techniques in dealing with characteristic applications to the prestress design of cable systems. As a further extension, the EFDM is applied to structures having some parts not yet geometrically defined, as can happen in designing new creative forms.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649242
|
oai_dc
|
Effects of geometric parameters on in-plane vibrations of two-stepped circular beams
|
Effects of geometric parameters on in-plane vibrations of two-stepped circular beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ekrem Tufekci(Istanbul Technical University); Oznur Ozdemirci Yigit(Istanbul Technical University)"
] |
In-plane free vibrations of circular beams with stepped cross-sections are investigated by using the exact analytical solution. The axial extension, transverse shear deformation and rotatory inertia effects are taken into account. The stepped arch is divided into a number of arches with constant crosssections. The exact solution of the governing equations is obtained by the initial value method. Several examples of arches with different step ratios, different locations of the steps, boundary conditions, opening angles and slenderness ratios for the first few modes are presented to illustrate the validity and accuracy of the method. The effects of the geometric parameters on the natural frequencies are investigated in details. Several examples in the literature are solved and the results are given in tables. The agreement of the results is good for all examples considered. The mode transition phenomenon is also observed for the stepped arches. Some examples are solved also numerically by using the commercial finite element program ANSYS.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649249
|
oai_dc
|
Parameter calibrations and application of micromechanical fracture models of structural steels
|
Parameter calibrations and application of micromechanical fracture models of structural steels
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Fangfang Liao(Tongji University); Wei Wang(Tongji University); Yiyi Chen(Tongji University)"
] |
Micromechanical facture models can be used to predict ductile fracture in steel structures. In order to calibrate the parameters in the micromechanical models for the largely used Q345 steel in China,uniaxial tensile tests, smooth notched tensile tests, cyclic notched bar tests, scanning electron microscope tests and finite element analyses were conducted in this paper. The test specimens were made from base metal, deposit metal and heat affected zone of Q345 steel to investigate crack initiation in welded steel connections. The calibrated parameters for the three different locations of Q345 steel were compared with that of the other seven varieties of structural steels. It indicates that the toughness index parameters in the stress modified critical strain (SMCS) model and the void growth model (VGM) are connected with ductility of the material but have no correlation with the yield strength, ultimate strength or the ratio of ultimate strength to yield strength. While the damage degraded parameters in the degraded significant plastic strain (DSPS) model and the cyclic void growth model (CVGM) and the characteristic length parameter are irrelevant with any properties of the material. The results of this paper can be applied to predict ductile fracture in welded steel connections.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649270
|
oai_dc
|
Dynamic analysis of semi-rigidly connected and partially embedded piles via the method of reverberation-ray matrix
|
Dynamic analysis of semi-rigidly connected and partially embedded piles via the method of reverberation-ray matrix
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wei Yan(Ningbo University); W.Q. Chen(Zhejiang University)"
] |
Free vibration and dynamic responses of piles semi-rigidly connected with the superstructures are investigated. Timoshenko beam theory is employed to characterize the pile partially embedded in a two-parameter elastic foundation. The formulations for the method of reverberation-ray matrix (MRRM)are then derived to investigate the dynamics of the pile with surface cracks, which are modeled as massless rotational springs. Comparison with existent numerical and experimental results indicates the proposed method is very effective and accurate for dynamic analysis, especially in the high frequency range. Finally, the effects of some physical parameters on the natural frequencies, frequency responses and transient responses of the piles are studied.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001649266
|
oai_dc
|
Prediction of seismic displacements in gravity retaining walls based on limit analysis approach
|
Prediction of seismic displacements in gravity retaining walls based on limit analysis approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohammad Mojallal(Tarbiat Moallem University); Ali Ghanbari(Tarbiat Moallem University)"
] |
Calculating the displacements of retaining walls under seismic loads is a crucial part in optimum design of these structures and unfortunately the techniques based on active seismic pressure are not sufficient alone for an appropriate design of the wall. Using limit analysis concepts, the seismic displacements of retaining walls are studied in present research. In this regard, applying limit analysis method and upper bound theorem, a new procedure is proposed for calculating the yield acceleration, critical angle of failure wedge, and permanent displacements of retaining walls in seismic conditions for two failure mechanisms, namely sliding and sliding-rotational modes. Also, the effect of internal friction angle of soil, the friction angle between wall and soil, maximum acceleration of the earthquake and height of the wall all in the magnitude of seismic displacements has been investigated by the suggested method. Two sets of ground acceleration records related to near-field and far-field domains are employed in analyses and eventually the results obtained from the suggested method are compared with those from other techniques.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704353
|
oai_dc
|
Experimental modal analysis of railway concrete sleepers with cracks
|
Experimental modal analysis of railway concrete sleepers with cracks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J.I. Real(Technical University of Valencia); M.E. Sánchez(Technical University of Valencia); T. Real(University of Alicante); F.J. Sánchez(Railway Division of Precon S.A.U.); C. Zamorano(Foundation for the Research and Engineering in Railways)"
] |
Concrete sleepers are essential components of the conventional railway. As support elements, sleepers are always subjective to a variety of time-dependent loads attributable to the train operations, either wheel or rail abnormalities. It has been observed that the sleepers may deteriorate due to these loads, inducing the formation of hairline cracks. There are two areas along the sleepers that are more prone to crack: the central and the rail seat sections. Several non-destructive methods have been developed to identify failures in structures. Health monitoring techniques are based on vibration responses measurements, which help engineers to identify the vibration-based damage or remotely monitor the sleeper health. In the present paper, the dynamic effects of the cracks in the vibration signatures of the railway pre-stressed concrete sleepers are investigated. The experimental modal analysis has been used to evaluate the modal bending changes in the vibration characteristics of the sleepers, differentiating between the central and the rail seat locations of the cracks. Modal parameters changes of the ‘healthy’ and cracked sleepers have been highlighted in terms of natural frequencies and modal damping. The paper concludes with a discussion of the most suitable failure indicator and it defines the vibration signatures of intact, central cracked and rail seat cracked sleepers.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704357
|
oai_dc
|
Interval finite element analysis of masonry-infilled walls
|
Interval finite element analysis of masonry-infilled walls
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ayse Erdolen(Yildiz Technical University); Bilge Doran(Yildiz Technical University)"
] |
This paper strongly addresses to the problem of the mechanical systems in which parameters are uncertain and bounded. Interval calculation is used to find sharp bounds of the structural parameters for infilled frame system modeled with finite element method. Infill walls are generally treated as nonstructural elements considerably to improve the lateral stiffness, strength and ductility of the structure together with the frame elements. Because of their complex nature, they are often neglected in the analytical model of building structures. However, in seismic design, ignoring the effect of infill wall in a numerical model does not accurately simulate the physical behavior. In this context, there are still some uncertainties in mechanical and also geometrical properties in the analysis and design procedure of infill walls. Structural uncertainties can be studied with a finite element formulation to determine sharp bounds of the structural parameters such as wall thickness and Young's modulus. In order to accomplish this sharp solution as much as possible, interval finite element approach can be considered, too. The structural parameters can be considered as interval variables by using the interval number, thus the structural stiffness matrix may be divided into the product of two parts which correspond to the interval values and the deterministic value.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704352
|
oai_dc
|
On the fatigue performance of Aluminum alloy 2024 scarfed lap joints
|
On the fatigue performance of Aluminum alloy 2024 scarfed lap joints
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"W.Z. Yan(Northwestern Polytechnical University); H.S. Gao(Northwestern Polytechnical University); X. Yuan(Northwestern Polytechnical University); F.S. Wang(Northwestern Polytechnical University); Z.F. Yue(Northwestern Polytechnical University)"
] |
A series of fatigue test were carried out on scarfed lap joints (SLJ) using in airfoil siding to explore the effect of structural details, such as rows of rivets, lap angles, on its fatigue performance. Finite element (FE) analysis was employed to explore the effect of lap angle on load transfer and the stress evolution around the rivet hole. At last, the fatigue lives were predicted by nominal stress approach and critical plane approach. Both of the test results and predicted results showed that fatigue life of SLJ was remarkably increased after introducing lap angle into the faying surface. Specimen with the lap angle of 1.68o exhibits the best fatigue performance in the present study.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704345
|
oai_dc
|
Response determination of a viscoelastic Timoshenko beam subjected to moving load using analytical and numerical methods
|
Response determination of a viscoelastic Timoshenko beam subjected to moving load using analytical and numerical methods
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohammad Tehrani(Shahrood University of Technology); H.R. Eipakchi(Shahrood University of Technology)"
] |
In this paper the dynamic behavior of a viscoelastic Timoshenko beam subjected to a concentrated moving load are studied analytically and numerically. The viscoelastic properties of the beam obey the linear standard model in shear and incompressible in bulk. The governing equation for Timoshenko beam theory is obtained in viscoelastic form using the correspondence principle. The analytical solution is based on the Fourier series and the numerical solution is performed with finite element method. The effects of the material properties and the load velocity are investigated on the responses by numerical and analytical methods. In addition, the results are compared with the Euler beam results.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704360
|
oai_dc
|
Post-buckling analysis of Timoshenko beams with temperature-dependent physical properties under uniform thermal loading
|
Post-buckling analysis of Timoshenko beams with temperature-dependent physical properties under uniform thermal loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Seref Doguscan Akbas(Yildiz Technical University); Turgut Kocatürk(Yildiz Technical University)"
] |
Post-buckling behavior of Timoshenko beams subjected to uniform temperature rising with temperature dependent physical properties are studied in this paper by using the total Lagrangian Timoshenko beam element approximation. The beam is clamped at both ends. In the case of beams with immovable ends, temperature rise causes compressible forces end therefore buckling and post-buckling phenomena occurs. It is known that post-buckling problems are geometrically nonlinear problems. Also, the material properties (Young’s modulus, coefficient of thermal expansion, yield stress) are temperature dependent: That is the coefficients of the governing equations are not constant in this study. This situation suggests the physical nonlinearity of the problem. Hence, the considered problem is both geometrically and physically nonlinear. The considered highly non-linear problem is solved considering full geometric non-linearity by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The beams considered in numerical examples are made of Austenitic Stainless Steel (316). The convergence studies are made. In this study, the difference between temperature dependent and independent physical properties are investigated in detail in post-buckling case. The relationships between deflections, thermal post-buckling configuration, critical buckling temperature, maximum stresses of the beams and temperature rising are illustrated in detail in post-buckling case.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704358
|
oai_dc
|
Nonlinear interaction behaviour of infilled frame-isolated footings-soil system subjected to seismic loading
|
Nonlinear interaction behaviour of infilled frame-isolated footings-soil system subjected to seismic loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ramakant Agrawal(TRUBA Institute of Engineering and Information Technology); M.S. Hora(Maulana Azad National Institute of Technology)"
] |
The building frame and its foundation along with the soil on which it rests, together constitute a complete structural system. In the conventional analysis, a structure is analysed as an independent frame assuming unyielding supports and the interactive response of soil-foundation is disregarded. This kind of analysis does not provide realistic behaviour and sometimes may cause failure of the structure. Also, the conventional analysis considers infill wall as non-structural elements and ignores its interaction with the bounding frame. In fact, the infill wall provides lateral stiffness and thus plays vital role in resisting the seismic forces. Thus, it is essential to consider its effect especially in case of high rise buildings. In the present research work the building frame, infill wall, isolated column footings (open foundation) and soil mass are considered to act as a single integral compatible structural unit to predict the nonlinear interaction behaviour of the composite system under seismic forces. The coupled isoparametric finite-infinite elements have been used for modelling of the interaction system. The material of the frame, infill and column footings has been assumed to follow perfectly linear elastic relationship whereas the well known hyperbolic soil model is used to account for the nonlinearity of the soil mass.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704355
|
oai_dc
|
Contact analysis of spherical ball and a deformable flat model with the effect of tangent modulus
|
Contact analysis of spherical ball and a deformable flat model with the effect of tangent modulus
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"V.C. Sathish Gandhi(Anna University); S. Ramesh(Sona College of Technology); R. Kumaravelan(Velalar College of Engineering and Technology); M. Thanmanaselvi(Anna University)"
] |
The paper is on contact analysis of a spherical ball with a deformable flat, considering the effect of tangent modulus on the contact parameters of a non-adhesive frictionless elastic-plastic contact. The contact analysis of this model has been carried out using analysis software Ansys and Abaqus. The contact parameters such as area of contact between two consecutive steps, volume of bulged material are evaluated from the formulated equations. The effect of the tangent modulus is considered for determining these parameters. The tangent modulus are accounted between 0.1E and 0.5E of materials E/Y value greater than 500 and less than 1750. Result shows that upto an optimal tangent modulus values the elastic core push up to the free surface in the flat. The simulation is also carried out in Abaqus and result provide evidence for the volume of bulged material in the contact region move up and flow into the free surface of the flat from the contact edge between the ball and flat. The strain energy of the whole model is varied between 20 to 40 percentage of the stipulated time for analysis.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001704349
|
oai_dc
|
Analytical solution for bending analysis of soft-core composite sandwich plates using improved high-order theory
|
Analytical solution for bending analysis of soft-core composite sandwich plates using improved high-order theory
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M.M. Kheirikhah(Islamic Azad University); S.M.R. Khalili(K.N. Toosi University of Technology); K. Malekzadeh Fard(Space Research Institute)"
] |
In the present paper, an improved high-order theory is used for bending analysis of soft-core sandwich plates. Third-order plate assumptions are used for face sheets and quadratic and cubic functions are assumed for transverse and in-plane displacements of the orthotropic soft core. Continuity conditions for transverse shear stresses at the interfaces as well as the conditions of zero transverse shear stresses on the upper and lower surfaces of the plate are satisfied. Also, transverse flexibility and transverse normal strain and stress of the orthotropic core are considered. The equations of motion and boundary conditions are derived by principle of minimum potential energy. Analytical solution for bending analysis of simply supported sandwich plates under various transverse loads are presented using Navier’s solution. Comparison of the present results with those of the three-dimensional theory of elasticity and some plate theories in the literature confirms the accuracy of the proposed theory.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709071
|
oai_dc
|
Time-history analysis based optimal design of space trusses: the CMA evolution strategy approach using GRNN and WA
|
Time-history analysis based optimal design of space trusses: the CMA evolution strategy approach using GRNN and WA
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Kaveh(an University of Science and Technology); M. Fahimi-Farzam(an University of Science and Technology); M. Kalateh-Ahani(Iran University of Science and Technology)"
] |
In recent years, the need for optimal design of structures under time-history loading aroused great attention in researchers. The main problem in this field is the extremely high computational demand of time-history analyses, which may convert the solution algorithm to an illogical one. In this paper, a new framework is developed to solve the size optimization problem of steel truss structures subjected to ground motions. In order to solve this problem, the covariance matrix adaptation evolution strategy algorithm is employed for the optimization procedure, while a generalized regression neural network is utilized as a meta-model for fitness approximation. Moreover, the computational cost of time-history analysis is decreased through a wavelet analysis. Capability and efficiency of the proposed framework is investigated via two design examples, comprising of a tower truss and a footbridge truss.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709043
|
oai_dc
|
Free vibrations of arbitrary quadrilateral thick plates with internal columns and uniform elastic edge supports by pb-2 Ritz method
|
Free vibrations of arbitrary quadrilateral thick plates with internal columns and uniform elastic edge supports by pb-2 Ritz method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"L.H. Wu(Shijiazhuang Tiedao University)"
] |
Free vibration analysis of arbitrary quadrilateral thick plates with internal columns and elastic edge supports is presented by using the powerful pb-2 Ritz method and Reddy’s third order shear deformation plate theory. The computing domain of arbitrary quadrilateral planform is mapped onto a standard square form by coordinate transformation. The versatile pb-2 Ritz functions defined by the product of a two-dimensional polynomial and a basic function are taken to be the admissible functions. Substituting these displacement functions into the energy functional and minimizing the total energy by differentiation, leads to a typical eigenvalue problem, which is solved by a standard eigenvalue solver. Stiffness and mass matrices are numerically integrated over the plate by using Gaussian quadrature. The accuracy and efficiency of the proposed method are demonstrated through several numerical examples by comparison and convergency studies. A lot of numerical results for reasonable natural frequency parameters of quadrilateral plates with different combinations of elastic boundary conditions and column supports at any locations are presented, which can be used as a benchmark for future studies in this area.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709075
|
oai_dc
|
Slope variation effect on large deflection of compliant beam using analytical approach
|
Slope variation effect on large deflection of compliant beam using analytical approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Khavaji(Babol Noshirvani University of Technology); D.D. Ganji(Babol Noshirvani University of Technology); N. Roshan(Babol Noshirvani University of Technology); R. Moheimani(Sharif University of Technology); M. Hatami(Babol Noshirvani University of Technology); A. Hasanpour(Babol Noshirvani University of Technology)"
] |
In this study the investigation of large deflections subject in compliant mechanisms is presented using homotopy perturbation method (HPM). The main purpose is to propose a convenient method of solution for the large deflection problem in compliant mechanisms in order to overcome the difficulty and complexity of conventional methods, as well as for the purpose of mathematical modeling and optimization. For simplicity, a cantilever beam of linear elastic material under horizontal, vertical and bending moment end point load is considered. The results show that the applied method is very accurate and capable for cantilever beams and can be used for a large category of practical problems for the aim of optimization. Also the consequence of effective parameters on the large deflection is analyzed and presented.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709065
|
oai_dc
|
A new method to calculate the equivalent stiffness of the suspension system of a vehicle
|
A new method to calculate the equivalent stiffness of the suspension system of a vehicle
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Pinbin Zhao(Jilin University); Guo-feng Yao(Jilin University); Min Wang(Jilin University); Xumin Wang(Jilin University); Jianhui Li(Jilin University)"
] |
The stiffness of a suspension system is provided by the bushings and the stiffness of the wheel center controls the suspension's elasto-kinematic (e-k) specification. So the stiffness of the wheel center is very important, but the stiffness of the wheel center is very hard to measure. The paper give a new method that we can use the stiffness of the bushings to calculate the equivalent stiffness of the wheel center, which can quickly and widely be used in all kinds of suspension structure. This method can also be used to optimize and design the suspension system. In the example we use the method to calculate the equivalent stiffness of the wheel center which meets the symmetric and positive conditions of the stiffness matrix.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709059
|
oai_dc
|
Non-linear free vibrations and post-buckling analysis of shear flexible functionally graded beams
|
Non-linear free vibrations and post-buckling analysis of shear flexible functionally graded beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K. Sanjay Anandrao(Advanced Systems Laboratory); R.K. Gupta(Advanced Systems Laboratory); P. Ramchandran(DRDL); G. Venkateswara Rao(Vardhaman College of Engineering)"
] |
Large amplitude free vibration and thermal post-buckling of shear flexible Functionally Graded Material (FGM) beams is studied using finite element formulation based on first order Timoshenko beam theory. Classical boundary conditions are considered. The ends are assumed to be axially immovable. The von-Karman type strain-displacement relations are used to account for geometric non-linearity. For all the boundary conditions considered, hardening type of non-linearity is observed. For large amplitude vibration of FGM beams, a comprehensive study has been carried out with various lengths to height ratios, maximum lateral amplitude to radius of gyration ratios, volume fraction exponents and boundary conditions. It is observed that, for FGM beams, the non-linear frequencies are dependent on the sign of the vibration amplitudes. For thermal post-buckling of FGM beams, the effect of shear flexibility on the structural response is discussed in detail for different volume fraction exponents, length to height ratios and boundary conditions. The effect of shear flexibility is observed to be predominant for clamped beam as compared to simply supported beam.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709053
|
oai_dc
|
Multidisciplinary optimization of collapsible cylindrical energy absorbers under axial impact load
|
Multidisciplinary optimization of collapsible cylindrical energy absorbers under axial impact load
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Mirzaei(Islamic Azad University); H. Akbarshahi(Amirkabir University of Technology); M. Shakeri(Amirkabir University of Technology); M. Sadighi(Amirkabir University of Technology)"
] |
In this article, the multi-objective optimization of cylindrical aluminum tubes under axial impact load is presented. The specific absorbed energy and the maximum crushing force are considered as objective functions. The geometric dimensions of tubes including diameter, length and thickness are chosen as design variables. D/t and L/D ratios are constricted in the range of which collapsing of tubes occurs in concertina or diamond mode. The Non-dominated Sorting Genetic Algorithm-II is applied to obtain the Pareto optimal solutions. A back-propagation neural network is constructed as the surrogate model to formulate the mapping between the design variables and the objective functions. The finite element software ABAQUS/Explicit is used to generate the training and test sets for the artificial neural networks. To validate the results of finite element model, several impact tests are carried out using drop hammer testing machine.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709048
|
oai_dc
|
Vibration and stability of axially loaded cracked beams
|
Vibration and stability of axially loaded cracked beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Murat Kisa(Harran University)"
] |
Structural defects such as cracks are the source of local flexibilities and cause deficiencies in structural resistance. In the engineering constructions, structural elements sometimes are subjected to axial loading. Therefore, besides crack ratios and locations, influence of applied load on the stability and dynamical characteristics should also be explored. This study offers a numerical technique for the vibration and stability analysis of axially loaded cracked beams. The model merges finite element and component mode synthesis methods. Initially, stability analysis is completed and then dynamical characteristics of beams are found. Very good conformities between outcomes of the current study and those in literature, give the confidence that proposed method is reliable and effective.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001709045
|
oai_dc
|
Influence of pressure-dependency of the yield criterion and temperature on residual stresses and strains in a thin disk
|
Influence of pressure-dependency of the yield criterion and temperature on residual stresses and strains in a thin disk
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Alexandrov(National Chung Cheng University); Y.R. Jeng(National Chung Cheng University); E. Lyamina(Russian Academy of Sciences)"
] |
Existing plane stress solutions for thin plates and disks have shown several qualitative features which are difficult to handle with the use of commercial numerical codes (non-existence of solutions, singular solutions, rapid growth of the plastic zone with a loading parameter). In order to understand the effect of temperature and pressure-dependency of the yield criterion on some of such features as well as on the distribution of residual stresses and strains, a semi-analytic solution for a thin hollow disk fixed to a rigid container and subject to thermal loading and subsequent unloading is derived. The material model is elastic-perfectly/plastic. The Drucker-Prager pressure-dependent yield criterion and the equation of incompressibity for plastic strains are adopted. The distribution of residual stresses and strains is illustrated for a wide range of the parameter which controls pressure-dependency of the yield criterion.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001663042
|
oai_dc
|
Flexural performance of fire damaged and rehabilitated two span reinforced concrete slabs and beams
|
Flexural performance of fire damaged and rehabilitated two span reinforced concrete slabs and beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jiang-Tao Yu(Tongji University); Yuan Liu(Tongji University); Zhou-Dao Lu(Tongji University); Kai Xiang(Tianjin Fire Research Institution of the Ministry of Public Security)"
] |
Five two-span reinforced concrete (RC) slabs and seven two-span RC beams were tested under the ISO 834 standard fire with different durations. CFRP strengthening was then applied to some of the specimens after the damaged concrete was removed from the specimens and replaced with polymer mortar. All the specimens were loaded to failure to investigate the influence of fire-damage and the effectiveness of strengthening methods. Test results indicated that the flexural capacities of specimens decrease with the fire duration increases. Moreover, fire exposure had more significant effect on the flexural rigidity than on the bearing capacity of the specimens. After rehabilitation, the bearing capacities of specimens reached or even exceeded that of the reference RC specimen, and the strengthening methods seemed to have limited effect on flexural rigidity recovery. From the analysis of moment redistribution of tested beams, elevated temperature is found having different impacts on sagging moment region and hogging moment region. The damage of RC continuous member is definitely a comprehensive response of different regions.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663068
|
oai_dc
|
Assessment of non-prismatic beams having symmetrical parabolic haunches with constant haunch length ratio of 0.5
|
Assessment of non-prismatic beams having symmetrical parabolic haunches with constant haunch length ratio of 0.5
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Bahadir Yuksel(Selcuk University)"
] |
Single span historic bridges often contain non-prismatic members identified with a varying depth along their span lengths. Commonly, the symmetric parabolic height variations having the constant haunch length ratio of 0.5 have been selected to lower the stresses at the high bending moment points and to maintain the deflections within the acceptable limits. Due to their non-prismatic geometrical configuration, their assessment, particularly the computation of fixed-end horizontal forces (FEFs) and fixed-end moments (FEMs) becomes a complex problem. Therefore, this study aimed to investigate the behavior of non-prismatic beams with symmetrical parabolic haunches (NBSPH) having the constant haunch length ratio of 0.5 using finite element analyses (FEA). FEFs and FEMs due to vertical loadings as well as the stiffness coefficients and the carry-over factors were computed through a comprehensive parametric study using FEA. It was demonstrated that the conventional methods using frame elements can lead to significant errors, and the deviations can reach to unacceptable levels for these types of structures.
Despite the robustness of FEA, the generation of FEFs and FEMs using the nodal outputs of the detailed finite element mesh still remains an intricate task. Therefore, this study advances to propose effective formulas and dimensionless estimation coefficients to predict the FEFs, FEMs, stiffness coefficients and carry-over factors with reasonable accuracy for the analysis and re-evaluation of the NBSPH. Using the proposed approach, the fixed-end reactions due to vertical loads, and also the stiffness coefficients and the carry-over factors of the NBSPH can be determined without necessitating the detailed FEA.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663038
|
oai_dc
|
A hybrid CSS and PSO algorithm for optimal design of structures
|
A hybrid CSS and PSO algorithm for optimal design of structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Kaveh(Iran University of Science and Technology); S. Talatahari(Tabriz University)"
] |
A new hybrid meta-heuristic optimization algorithm is presented for design of structures. The algorithm is based on the concepts of the charged system search (CSS) and the particle swarm optimization (PSO) algorithms. The CSS is inspired by the Coulomb and Gauss’s laws of electrostatics in physics, the governing laws of motion from the Newtonian mechanics, and the PSO is based on the swarm intelligence and utilizes the information of the best fitness historically achieved by the particles (local best) and by the best among all the particles (global best). In the new hybrid algorithm, each agent is affected by local and global best positions stored in the charged memory considering the governing laws of electrical physics. Three different types of structures are optimized as the numerical examples with the new algorithm. Comparison of the results of the hybrid algorithm with those of other metaheuristic algorithms proves the robustness of the new algorithm.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663064
|
oai_dc
|
A one-dimensional model for impact forces resulting from high mass, low velocity debris
|
A one-dimensional model for impact forces resulting from high mass, low velocity debris
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K. Paczkowski(University of Hawaii at Manoa); H.R. Riggs(University of Hawaii at Manoa); C.J. Naito(Lehigh University); A. Lehmann(Lehigh University)"
] |
Impact from water-borne debris during tsunami and flood events pose a potential threat to structures. Debris impact forces specified by current codes and standards are based on rigid body dynamics, leading to forces that are dependent on total debris mass. However, shipping containers and other debris are unlikely to be rigid compared to the walls, columns and other structures that they impact. The application of a simple one-dimensional model to obtain impact force magnitude and duration, based on acoustic wave propagation in a flexible projectile, is explored. The focus herein is on in-air impact. Based on small-scale experiments, the applicability of the model to predict actual impact forces is investigated. The tests show that the force and duration are reasonably well represented by the simple model, but they also show how actual impact differs from the ideal model. A more detailed threedimensional finite element model is also developed to understand more clearly the physical phenomena involved in the experimental tests. The tests and the FE results reveal important characteristics of actual impact, knowledge of which can be used to guide larger scale experiments and detailed modeling. The one-dimensional model is extended to consider water-driven debris as well. When fluid is used to propel the 1-D model, an estimate of the ‘added mass’ effect is possible. In this extended model the debris impact force depends on the wave propagation in the two media, and the conditions under which the fluid increases the impact force are discussed.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663070
|
oai_dc
|
Numerical study on thin plates under the combined action of shear and tensile stresses
|
Numerical study on thin plates under the combined action of shear and tensile stresses
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Sathiyaseelan(National Institute of Technology); K. Baskar(National Institute of Technology)"
] |
Analytical (Rayleigh-Ritz method) and numerical studies are carried out and buckling interaction curves are developed for simply supported plates of varying aspect ratios ranging from 1 to 5, under the combined action of in-plane shear and tension. A multi-step buckling procedure is employed in the Finite Element (FE) model instead of a regular single step analysis in view of obtaining the buckling load under the combined forces. Both the analytical (classical) and FE studies confirm the delayed shear buckling characteristics of thin plate under the combined action of shear and tension. The interaction curves are found to be linear and are found to vary with plate aspect ratio. The interaction curve developed using Rayleigh-Ritz method is found to deviate in an increasing trend from that of validated FE model as plate aspect ratio is increased beyond value of 1. It is found that the observed deviation is due to the insufficient number of terms that is been considered in the assumed deflection function of Rayleigh-Ritz method and a convergence study is suggested as a solution.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663074
|
oai_dc
|
Yield line mechanism analysis of cold-formed channel sections with edge stiffeners under bending
|
Yield line mechanism analysis of cold-formed channel sections with edge stiffeners under bending
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Maduliat(Monash University); M.R. Bambach(University of New South Wales); X.L. Zhao(Monash University)"
] |
Cold-formed channel sections are used in a variety of applications in which they are required to absorb deformation energy. This paper investigates the collapse behaviour and energy absorption capability of cold-formed steel channels with flange edge stiffeners under large deformation major-axis bending. The Yield Line Mechanism technique is applied using the energy method, and based upon measured spatial plastic collapse mechanisms from experiments. Analytical solutions for the collapse curve and in-plane rotation capacity are developed, and used to model the large deformation behaviour and energy absorption. The analytical results are shown to compare well with experimental values. Due to the complexities of the yield line model of the collapse mechanism, a simplified procedure to calculate the energy absorbed by channel sections under large bending deformation is developed and also shown to compare well with the experiments.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663015
|
oai_dc
|
Effects of dead loads on the static analysis of plates
|
Effects of dead loads on the static analysis of plates
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hideo Takabatake(Kanazawa Institute of Technology)"
] |
The collapse of structures due to snow loads on roofs occurs frequently for steel structures and rarely for reinforced concrete structures. Since the most significant difference between these structures is related to their ability to handle dead loads, dead loads are believed to play an important part in the collapse of structures by snow loads. As such, the effect of dead loads on displacements and stress couples produced by live loads is presented for plates with different edge conditions. The governing equation of plates that takes into account the effect of dead loads is formulated by means of Hamilton’s principle. The existence and effect of dead loads are proven by numerical calculations based on the Galerkin method. In addition, a closed-form solution for simply supported plates is proposed by solving, in approximate terms, the governing equation that includes the effect of dead loads, and this solution is then examined. The effect of dead loads on static live loads can be explained explicitly by means of this closed-form solution. A method that reflects the effects of dead loads on live loads is presented as an example. The present study investigates an additional factor in lightweight roof structural elements, which should be considered due to their recent development.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001663053
|
oai_dc
|
Integrated fire dynamic and thermomechanical modeling of a bridge under fire
|
Integrated fire dynamic and thermomechanical modeling of a bridge under fire
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Joonho Choi(Georgia Institute of Technology); Rami Haj-Ali(Georgia Institute of Technology); 김희선(이화여자대학교)"
] |
This paper proposes a nonlinear computational modeling approach for the behaviors of structural systems subjected to fire. The proposed modeling approach consists of fire dynamics analysis, nonlinear transient-heat transfer analysis for predicting thermal distributions, and thermomechanical analysis for structural behaviors. For concretes, transient heat formulations are written considering temperature dependent heat conduction and specific heat capacity and included within the thermomechanical analyses. Also, temperature dependent stress-strain behaviors including compression hardening and tension softening effects are implemented within the analyses. The proposed modeling technique for transient heat and thermomechanical analyses is first validated with experimental data of reinforced concrete (RC) beams subjected to high temperatures, and then applied to a bridge model. The bridge model is generated to simulate the fire incident occurred by a gas truck on April 29, 2007 in Oakland California, USA. From the simulation, not only temperature distributions and deformations of the bridge can be found, but critical locations and time frame where collapse occurs can be predicted. The analytical results from the simulation are qualitatively compared with the real incident and show good agreements.
|
토목공학
| null |
http://dx.doi.org/
|
kci_detailed_000075.xml
|
||
ART001608587
|
oai_dc
|
Frictionless contact problem for a layer on an elastic half plane loaded by means of two dissimilar rigid punches
|
Frictionless contact problem for a layer on an elastic half plane loaded by means of two dissimilar rigid punches
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Talat Sukru Ozsahin(Karadeniz Technical University)"
] |
The contact problem for an elastic layer resting on an elastic half plane is considered according to the theory of elasticity with integral transformation technique. External loads P and Q are transmitted to the layer by means of two dissimilar rigid flat punches. Widths of punches are different and the thickness of the layer is h. All surfaces are frictionless and it is assumed that the layer is subjected to uniform vertical body force due to effect of gravity. The contact along the interface between elastic layer and half plane will be continuous, if the value of load factor, λ, is less than a critical value, λcr. However, if tensile tractions are not allowed on the interface, for λ > λcr the layer separates from the interface along a certain finite region. First the continuous contact problem is reduced to singular integral equations and
solved numerically using appropriate Gauss-Chebyshev integration formulas. Initial separation loads, λcr , initial separation points, xcr, are determined. Also the required distance between the punches to avoid any separation between the punches and the layer is studied and the limit distance between punches that ends interaction of punches, is investigated. Then discontinuous contact problem is formulated in terms of singular integral equations. The numerical results for initial and end points of the separation region, displacements of the region and the contact stress distribution along the interface between elastic layer and half plane is determined for various dimensionless quantities.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608594
|
oai_dc
|
An endochronic model of material function and its application to plastic behavior of metals under asymmetric cyclic loadings
|
An endochronic model of material function and its application to plastic behavior of metals under asymmetric cyclic loadings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wei-Ching Yeh(National Central University); Hsi-Yen Lin(Intellectual Property Office); Jhen-Bo Jhao(National Central University)"
] |
By using the incremental form of the endochronic theory of plasticity, a model of material function is proposed in this paper to investigate plastic behavior. By comparing the stress-strain hysteresis loop, the theory is shown to agree well with the experimental results, especially in the evolution of peak stress values of SAE 4340 steel loaded by cyclic loading with various amplitudes. Depending on the choice of material parameters, the present model can substantially result in six categories of material function, each of which can behave differently with respect to an identical deformation history. In addition, the present model of material function is shown to be capable of describing the behavior of erasure of memory of materials, as experimentally observed by Lamba and Sidebottom (1978).
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608591
|
oai_dc
|
An assumed-stress hybrid element for static and free vibration analysis of folded plates
|
An assumed-stress hybrid element for static and free vibration analysis of folded plates
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kutlu Darilmaz(Istanbul Technical University)"
] |
A four-node hybrid stress element for analysing orthotropic folded plate structures is presented. The formulation is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. The proposed element has six
degree of freedom per node and permits an easy connection to other type of elements. An equilibrated stress field in each element and inter element compatible boundary displacement field are assumed independently. Static and free vibration analyses of folded plates are carried out on numerical examples to show that the validity and efficiency of the present element.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608598
|
oai_dc
|
Consistent thermal analysis procedure of LNG storage tank
|
Consistent thermal analysis procedure of LNG storage tank
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Se-Jin Jeong(Chungnam National University Hospital & Medical School); Byeong-Moo Jin(DAEWOO E&C); Young-Jin Kim(Institute of Construction Technology); Chul-Hun Chung(Dankook University)"
] |
As the LNG (Liquefied Natural Gas) tank contains cryogenic liquid, realistic thermal analyses are of a primary importance for a successful design. The structural details of the LNG tank are so complicated that some strategies are necessary to reasonably predict its temperature distribution. The proposed heat transfer model can consider the beneficial effects of insulation layers and a suspended deck on temperature distribution of the outer concrete tank against cryogenic conditions simply by the boundary conditions of the outer tank model. To this aim, the equilibrium condition or heat balance in a steady state is utilized in a various way, and some aspects of heat transfer via conduction, convection and radiation are implemented as necessary. Overall thermal analysis procedures for the LNG tank are revisited to examine some unjustifiable assumptions of conventional analyses. Concrete and insulation
properties under cryogenic condition and a reasonable conversion procedure of the temperature-induced nonlinear stress into the section forces are discussed. Numerical examples are presented to verify the proposed schemes in predicting the actual temperature and stress distributions of the tank as affected by the cryogenic LNG for the cases of normal operation and leakage from the inner steel tank. It is expected that the proposed schemes enable a designer to readily detect the effects of insulation layers and a
suspended deck and, therefore, can be employed as a useful and consistent tool to evaluate the thermal effect in a design stage of an LNG tank as well as in a detailed analysis.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608584
|
oai_dc
|
Static finite element analysis of architectural glass curtain walls under in-plane loads and corresponding full-scale test
|
Static finite element analysis of architectural glass curtain walls under in-plane loads and corresponding full-scale test
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.M. Memari(The Pennsylvania State University); A. Shirazi(The Pennsylvania State University); P.A. Kremer(The Pennsylvania State University)"
] |
A pilot study has been conducted to guide the development of a finite element modeling formulation for the analysis of architectural glass curtain walls under in-plane lateral load simulating earthquake effects. This pilot study is one aspect of ongoing efforts to develop a general prediction model for glass cracking and glass fallout for architectural glass storefront and curtain wall systems during seismic loading. For this study, the ANSYS finite element analysis program was used to develop a model and obtain the stress distribution within an architectural glass panel after presumed seismic movements cause glass-to-frame contact. The analysis was limited to static loading of a dry-glazed glass curtain wall panel. A mock-up of the glass curtain wall considered in the analysis with strain gages mounted at select
locations on the glass and the aluminum framing was subjected to static loading. A comparison is made between the finite element analysis predicted strain and the experimentally measured strain at each strain gage location.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608577
|
oai_dc
|
Stresses in FGM pressure tubes under non-uniform temperature distribution
|
Stresses in FGM pressure tubes under non-uniform temperature distribution
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ahmet N. Eraslan(Middle East Technical University)"
] |
The effects of material nonhomogeneity and nonisothermal conditions on the stress response of pressurized tubes are assessed by virtue of a computational model. The modulus of elasticity, the Poisson’s ratio, the yield strength, and the coefficient of thermal expansion, are assumed to vary
nonlinearly in the tube. A logarithmic temperature distribution within the tube is proposed. Under these conditions, it is shown that the stress states and the magnitudes of response variables are affected significantly by both the material nonhomogeneity and the existence of the radial temperature gradient.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608566
|
oai_dc
|
Direct frequency domain analysis of concrete arch dams based on FE-BE procedure
|
Direct frequency domain analysis of concrete arch dams based on FE-BE procedure
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Vahid Lotfi†(Amirkabir University of Technology)"
] |
A FE-BE procedure is presented for dynamic analysis of concrete arch dams. In this technique, dam body is discretized by finite elements, while foundation rock is handled by three dimensional boundary element formulation. This would allow a rigorous inclusion of dam-foundation rock interaction, with no limitations imposed on geometry of canyon shape. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various ratios of foundation rock to dam concrete elastic moduli under an empty reservoir condition. Furthermore, the effects of canyon shape on response of dam, is also discussed.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608573
|
oai_dc
|
Sliding mode control based on neural network for the vibration reduction of flexible structures
|
Sliding mode control based on neural network for the vibration reduction of flexible structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zi-chen Deng(Northwestern Polytechnical University); Yong-an Huang(Northwestern Polytechnical University); Wen-cheng Li(Northwestern Polytechnical University)"
] |
A discrete sliding mode control (SMC) method based on hybrid model of neural network and nominal model is proposed to reduce the vibration of flexible structures, which is a robust active controller developed by using a sliding manifold approach. Since the thick boundary layer will reduce the
virtue of SMC, the multilayer feed-forward neural network is adopted to model the uncertainty part. The neural network is trained by Levenberg-Marquardt backpropagation. The design objective of the sliding mode surface is based on the quadratic optimal cost function. In course of running, the input signal of
SMC come from the hybrid model of the nominal model and the neural network. The simulation shows that the proposed control scheme is very effective for large uncertainty systems.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608588
|
oai_dc
|
Numerical simulation of columns with un-bonded reinforcing bars for crack control
|
Numerical simulation of columns with un-bonded reinforcing bars for crack control
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G. Chen(Queensland University of Technology); H. Fukuyama(Building Research Institute); M. Teshigawara(Building Research Institute); H. Etoh(Building Research Institute); K. Kusunoki(Building Research Institute); H. Suwada(Building Research Institute)"
] |
Following previous work carried out in Building Research Institute in Japan, finite element analyses of conceptual column designs are performed in this paper. The effectiveness of the numerical model is evaluated by experimental tests and parametric studies are conducted to determine influential factors in conceptual column designs. First, three different column designs are analysed: bonded, unbonded, and un-bonded with additional reinforcing bars. The load-displacement curves and cracking patterns in concrete are obtained and compared with experimental ones. The comparisons indicate that the finite element model is able to reflect the experimental results closely. Both numerical and experimental results show that, the introduction of un-bonded zones in a column end can reduce cracking strains, accordingly reduce the stiffness and strength as well; the addition of extra reinforcement in the un-bonded zones can offset the losses of the stiffness and strength. To decide the proper length of the un-bonded zones and the sufficient amount of the additional reinforcing bars, parametric studies are carried out on their influences. It has been found that the stiffness of un-bonded designs slightly decreases with increasing the length of the un-bonded zones and increases with the size of the additional reinforcing bars.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001608595
|
oai_dc
|
Repair of precracked RC rectangular shear beams using CFRP strip technique
|
Repair of precracked RC rectangular shear beams using CFRP strip technique
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J. Jayaprakash(Universiti Putra Malaysia); Abdul Aziz Abdul Samad(Universiti Tun Hussein Onn Malaysia); Ashrabov Anvar Abbasovich(Tashkent Automobile and Road Construction Institute); Abang Abdullah Abang Ali(Universiti Putra Malaysia)"
] |
The exploitation of fibre reinforced polymer composites, as external reinforcement is an evergreen and well-known technique for improving the structural performance of reinforced concrete structures. The demand to use FRP composites in the civil engineering industry is mainly due to its high
strength, light weight, and stiffness. This paper exemplifies the shear strength of partially precracked reinforced concrete rectangular beams repaired with externally bonded Bi-Directional Carbon Fibre Reinforced Polymer (CFRP) Fabrics strips. All specimens were cast in the laboratory environment without
any internal shear reinforcement. The test parameters were longitudinal tensile reinforcement, shear span to effective depth ratio, spacing of CFRP strips, and orientation of CFRP reinforcement. It mainly focuses
on the shear capacity and modes of failure of the CFRP strengthened shear beams. Results have shown that the CFRP repaired beams attained a shear enhancement of 32% and 107.64% greater than the control beams. This study underscores that the CFRP strip technique significantly enhanced the shear capacity of precracked reinforced concrete rectangular beams without any internal shear reinforcement.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591730
|
oai_dc
|
Experimental and theoretical research on the compression performance of CFRP sheet confined GFRP short pole
|
Experimental and theoretical research on the compression performance of CFRP sheet confined GFRP short pole
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Li Chen(PLA University of Science and Technology); Qilin Zhao(PLA University of Science and Technology); Kebin Jiang(PLA University of Science and Technology)"
] |
The axial compressive strength of unidirectional FRP is generally quite lower than its axial tensile strength. This fact decreases the advantages of FRP as main load bearing member in engineering structure. In order to restrain the lateral expansion and splitting of GFRP, and accordingly heighten its axial compressive bearing capacity, a project that to confine GFRP pole with surrounding CFRP sheet is suggested in the present study. The Experiment on the CFRP sheet confined GFRP poles showed that a combined structure of high bearing capacity was attained. Basing on the experiment research a theoretical iterative calculation approach is suggested to predict the ultimate axial compressive stress of the combined structure, and the predicted results agree well with the experimental results. Then the influences of geometrical parameters on the ultimate axial compressive stress of the combined structure are also analyzed basing on this approach.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591735
|
oai_dc
|
Large deflection analysis of laminated composite plates using layerwise displacement model
|
Large deflection analysis of laminated composite plates using layerwise displacement model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Cetkovic(University of Belgrade); Dj. Vuksanovic(University of Belgrade)"
] |
In this paper the geometrically nonlinear continuum plate finite element model, hitherto not reported in the literature, is developed using the total Lagrange formulation. With the layerwise displacement field of Reddy, nonlinear Green-Lagrange small strain large displacements relations (in the von Karman sense) and linear elastic orthotropic material properties for each lamina, the 3D elasticity equations are reduced to 2D problem and the nonlinear equilibrium integral form is obtained. By performing the linearization on nonlinear integral form and then the discretization on linearized integral form, tangent stiffness matrix is obtained with less manipulation and in more consistent form, compared to the one obtained using laminated element approach. Symmetric tangent stiffness matrixes, together with internal force vector are then utilized in Newton Raphson’s method for the numerical solution of nonlinear incremental finite element equilibrium equations. Despite of its complex layer dependent numerical nature, the present model has no shear locking problems, compared to ESL (Equivalent Single Layer) models, or aspect ratio problems, as the 3D finite element may have when analyzing thin plate behavior. The originally coded MATLAB computer program for the finite element solution is used to verify the accuracy of the numerical model, by calculating nonlinear response of plates with different mechanical properties, which are isotropic, orthotropic and anisotropic (cross ply and angle ply), different plate thickness, different boundary conditions and different load direction (unloading/loading). The obtained results are compared with available results from the literature and the linear solutions from the author's previous papers.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591723
|
oai_dc
|
Roller compacted concrete pavements reinforced with steel and polypropylene fibers
|
Roller compacted concrete pavements reinforced with steel and polypropylene fibers
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Morteza Madhkhan(Isfahan University of Technology (IUT)); Rasool Azizkhani(Isfahan University of Technology (IUT)); Mohammad E. Torki(Sharif University of Technology (SUT))"
] |
In this paper, the effects of both pozzolans and (steel and poly-propylene) fibers on the mechanical properties of roller compacted concrete are studied. Specimens for the experiments were made using a soil-based approach; thus, the Kango’s vibration hammer was used for compaction. The tests in the first stage were carried out to determine the optimal moisture requirements for mix designs using cubic 150 × 150 × 150 mm specimens. In the tests of the second stage, the mechanical behaviors of the main specimens made using the optimal moisture obtained in the previous stage were evaluated using 28, 90, and 210 day cubic specimens. The mechanical properties of RCC pavements were evaluated using a soil-based compaction method and the optimum moisture content obtained from the pertaining experiments, and by adding different percentages of Iranian pozzolans as well as different amounts of steel fibers, each one accompanied by 0.1% of poly-propylene fibers. Using pozzolans, maximum increase in compressive strength was observed to occur between 28 and 90 days of age, rupture modulus was found to decrease, but toughness indices did not change considerably. The influence of steel fibers on compressive strength was often more significant than that of PP fibers, but neither steel nor PP fibers did contribute to increase in the rupture modulus independently. Also, the toughness indices increased when steel fibers were used.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591740
|
oai_dc
|
Generalized curved beam on elastic foundation solved by transfer matrix method
|
Generalized curved beam on elastic foundation solved by transfer matrix method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Marcello Arici(Università di Palermo); Michele Fabio Granata(Università di Palermo)"
] |
A solution of space curved bars with generalized Winkler soil found by means of Transfer Matrix Method is presented. Distributed, concentrated loads and imposed strains are applied to the beam as well as rigid or elastic boundaries are considered at the ends. The proposed approach gives the analytical and numerical exact solution for circular beams and rings, loaded in the plane or perpendicular to it. A well-approximated solution can be found for general space curved bars with complex geometry. Elastic foundation is characterized by six parameters of stiffness in different directions: three for rectilinear springs and three for rotational springs. The beam has axial, shear, bending and torsional stiffness. Numerical examples are given in order to solve practical cases of straight and curved foundations. The presented method can be applied to a wide range of problems, including the study of tanks, shells and complex foundation systems. The particular case of box girder distortion can also be studied through the beam on elastic foundation (BEF) analogy.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591728
|
oai_dc
|
A refined finite element for first-order plate and shell analysis
|
A refined finite element for first-order plate and shell analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"한성천(Daewon University College); Worsak Kanok-Nukulchai(Asian Institute of Technology); Won-Hong Lee(Gyeongnam National University of Science and Technology)"
] |
This paper presents an improved 8-node shell element for the analysis of plates and shells. The finite element, based on a refined first-order shear deformation theory, is further improved by the combined use of assumed natural strain method. We analyze the influence of the shell element with the different patterns of sampling points for interpolating different components of strains. Using the assumed natural strain method with proper interpolation functions, the present shell element generates neither membrane nor shear locking behavior even when full integration is used in the formulation. Further, a refined first-order shear deformation theory, which results in parabolic through-thickness distribution of the transverse shear strains from the formulation based on the third-order shear deformation theory, is proposed. This formulation eliminates the need for shear correction factors in the first-order theory. Numerical examples demonstrate that the present element perform better in comparison with other shell elements.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591734
|
oai_dc
|
Correction of node mapping distortions using universal serendipity elements in dynamical problems
|
Correction of node mapping distortions using universal serendipity elements in dynamical problems
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Semih Küçükarslan(Istanbul Technical University); Ali Demir(Celal Bayar University)"
] |
In this paper, the use of universal serendipity elements (USE) to eliminate node mapping distortions for dynamic problem is presented. Rectangular shaped elements for USE are being introduced by using a flexible master element with an adjustable edge node location. The shape functions of the universal serendipity formulation are used to derive the mass and damping matrices for the dynamic analyses. These matrices eliminate the node mapping distortion errors that occurs incase of the standard shape function formulations. The verification of new formulation will be tested and the errors encountered in the standard formulation will be studied for a dynamically loaded deep cantilever.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591732
|
oai_dc
|
Model predictive control strategies for protection of structures during earthquakes
|
Model predictive control strategies for protection of structures during earthquakes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Long-He Xu(Beijing Jiaotong University); Zhong-Xian Li(Tianjin University)"
] |
This paper presents a theoretical study of a model predictive control (MPC) strategy employed in semi-active control system with magnetorheological (MR) dampers to reduce the responses of seismically excited structures. The MPC scheme is based on a prediction model of the system response to obtain the control actions by minimizing an objective function, which can compensate for the effect of time delay that occurred in real application. As an example, a 5-story building frame equipped with two 20 kN MR dampers is presented to demonstrate the performance of the proposed MPC scheme for addressing time delay and reducing the structural responses under different earthquakes, in which the predictive length l = 5 and the delayed time step d = 10, 20, 40, 60, 100 are considered. Comparison with passive-off, passive-on, and linear quadratic Gaussian (LQG) control strategy indicates that MPC scheme exhibits good control performance similar to the LQG control strategy, both have better control effectiveness than two passive control methods for most cases, and the MPC scheme used in semi-active control system show more effectiveness and robustness for addressing time delay and protecting structures during earthquakes.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001591726
|
oai_dc
|
Characterization and shaking table tests of multiple trench friction pendulum system with numerous intermediate sliding plates
|
Characterization and shaking table tests of multiple trench friction pendulum system with numerous intermediate sliding plates
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"C.S. Tsai(Feng Chia University); Yung-Chang Lin(Feng Chia University)"
] |
In order to upgrade the seismic resistibility of structures and enhance the functionality of an isolator, a new base isolator called the multiple trench friction pendulum system (MTFPS) is proposed in this study. The proposed MTFPS isolator is composed of a trench concave surface and several intermediate sliding plates in two orthogonal directions. Mathematical formulations have been derived to examine the characteristics of the proposed MTFPS isolator possessing numerous intermediate sliding plates. By means of mathematical formulations which have been validated by experimental results of bidirectional ground shaking, it can be inferred that the natural period and damping effect of the MTFPS isolator with several intermediate sliding plates can be altered continually and controllably during earthquakes. Furthermore, results obtained from the component and shaking table tests demonstrate that the proposed isolator provides good protection to structures for prevention of damage from strong earthquakes.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550953
|
oai_dc
|
Multicut high dimensional model representation for reliability analysis
|
Multicut high dimensional model representation for reliability analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rajib Chowdhury(Swansea University); B.N. Rao(Indian Institute of Technology Madras)"
] |
This paper presents a novel method for predicting the failure probability of structural or mechanical systems subjected to random loads and material properties involving multiple design points. The method involves Multicut High Dimensional Model Representation (Multicut-HDMR) technique in conjunction with moving least squares to approximate the original implicit limit state/performance function with an explicit function. Depending on the order chosen sometimes truncated Cut-HDMR expansion is unable to approximate the original implicit limit state/performance function when multiple design points exist on the limit state/performance function or when the problem domain is large. Multicut-HDMR addresses this problem by using multiple reference points to improve accuracy of the approximate limit state/performance function. Numerical examples show the accuracy and efficiency of the proposed approach in estimating the failure probability.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550948
|
oai_dc
|
Solution of periodic notch problems in an infinite plate using BIE in conjunction with remainder estimation technique
|
Solution of periodic notch problems in an infinite plate using BIE in conjunction with remainder estimation technique
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Y.Z. Chen(Jiangsu University)"
] |
This paper provides a complex variable BIE for solving the periodic notch problems in plane plasticity. There is no limitation for the configuration of notches. For the periodic notch problem, the remainder estimation technique is suggested. In the technique, the influences on the central notch from many neighboring notches are evaluated exactly. The influences on the central notch from many remote notches are approximated by one term with a multiplying factor. This technique provides an effective way to solve the problems of periodic structures. Several numerical examples are presented, and most of them have not been reported previously.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550951
|
oai_dc
|
Some characteristics of an interior explosion within a room without venting
|
Some characteristics of an interior explosion within a room without venting
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"V.R. Feldgun(National Building Research Institute); Y.S. Karinski(National Building Research Institute); D.Z. Yankelevsky(National Building Research Institute)"
] |
The paper presents a study aimed at understanding some characteristics of an interior explosion within a room with limited or no venting. The explosion may occur in ammunition storage or result from a terrorist action or from a warhead that had penetrated into this room. The study includes numerical simulations of the problem and analytical derivations. Different types of analysis (1-D, 2-D and 3-D analysis) were performed for a room with rigid walls and the results were analyzed. For the 3D problem the effect of the charge size and its location within the room was investigated and a new insight regarding the pressure distribution on the interior wall as function of these parameters has been gained. The numerical analyses were carried out using the Eulerian multi-material approach. Further, an approximate analytical formula to predict the residual internal pressure was developed. The formula is based on the conservation law of total energy and its implementation yields very good agreement with the results obtained numerically using the complete statement of the problem for a wide range of explosive weights and room sizes that is expressed through a non-dimensional parameter. This new formula is superior to existing literature recommendations and compares considerably better with the above numerical results.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550942
|
oai_dc
|
Analytical solutions for skewed thick plates subjected to transverse loading
|
Analytical solutions for skewed thick plates subjected to transverse loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Pang-jo Chun(Ehime University); Gongkang Fu(Wayne State University); 임윤묵(Yonsei University)"
] |
This paper presents analytical solutions for skewed thick plates under transverse loading that have previously been unreported in the literature. The thick plate solution is obtained in a framework of an oblique coordinate system. The governing equation is first derived in the oblique coordinate system, and the solution is obtained using deflection and rotation as partial derivatives of a potential function developed in this research. The solution technique is applied to three illustrative application examples, and the results are compared with numerical solutions in the literature and those derived from the commercial finite element analysis package ANSYS 11. These results are in excellent agreement. The present solution may also be used to model skewed structures such as skewed bridges, to facilitate efficient routine design or evaluation analyses, and to form special elements for finite element analysis. At the same time, the analytical solution developed in this research could be used to develop methods to address post-buckling and dynamic problems.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550955
|
oai_dc
|
Flexural strength of prestressed concrete members with unbonded tendons
|
Flexural strength of prestressed concrete members with unbonded tendons
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"이득행(University of Seoul); 김강수(서울시립대학교)"
] |
It is difficult to accurately predict the flexural strength of prestressed members with unbonded tendons, unlike that of prestressed members with bonded tendons, due to the unbonded behavior between concrete and tendon. While there have been many studies on this subject, the flexural strength of prestressed members with unbonded tendons is still not well understood, and different standards in various countries often result in different estimation results for identical members. Therefore, this paper aimed to observe existing approaches and to propose an improved model for the ultimate strength of prestressed members with unbonded tendons. Additionally, a large number of tests results on flexural strength of prestressed members with unbonded tendons were collected from previous studies, which entered into a database to verify the accuracy of the proposed model. The proposed model, compared to existing approaches, well estimated the flexural strength of prestressed members with unbonded tendons, adequately reflecting the effects of influencing factors such as the reinforced steel ratio, the loading patterns, and the concrete strength. The proposed model also provided a reasonably good estimation of the ultimate strength of over-reinforced members and high-strength concrete members.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550944
|
oai_dc
|
Analytic solution for the interaction between a viscoelastic Bernoulli-Navier beam and a winkler medium
|
Analytic solution for the interaction between a viscoelastic Bernoulli-Navier beam and a winkler medium
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Claudio Floris(Politecnico di Milano); Francesco Paolo Lamacchia(Politecnico di Milano)"
] |
This paper deals with the problem of the determination of the response of a viscoelastic Bernoulli-Navier beam, which is resting on an elastic medium. Assuming uniaxial bending, the displacement of the beam axis is governed by an integro-differential equation. The compatibility of the displacements between the beam and the elastic medium is imposed through an integral equation. In general and in particular in the case of a Boussinesq medium, the solution has to be pursued numerically. On the contrary, in the case of a Winkler’s medium the compatibility equation becomes a linear finite relationship, which allows finding an original analytical solution of the problem for both hereditary and aging behavior of the beam. Some numerical examples complete the paper, in which a comparison is made between the hereditary and the aging model for the creep of the beam.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001550943
|
oai_dc
|
Nonlinear analysis of finite beam resting on Winkler foundation with consideration of beam-soil interface resistance effect
|
Nonlinear analysis of finite beam resting on Winkler foundation with consideration of beam-soil interface resistance effect
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"L. Zhang(L. Zhang); M.H. Zhao(Hunan University); Y. Xiao(Hunan University); B.H. Ma(Hunan University)"
] |
Comprehensive and accurate analysis of a finite foundation beam is a challenging engineering problem and an important subject in foundation design. One of the limitation of the traditional Winkler elastic foundation model is that the model neglects the effect of the interface resistance between the beam and the underneath foundation soil. By taking the beam-soil interface resistance into account, a deformation governing differential equation for a finite beam resting on the Winkler elastic foundation is developed. The coupling effect between vertical and horizontal displacements is also considered in the presented method. Using Galerkin method, semi-analytical solutions for vertical and horizontal displacements, axial force, shear force and bending moment of the beam under symmetric loads are presented. The influences of the interface resistance on the behavior of foundation beam are also investigated.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595708
|
oai_dc
|
Behavior of reinforced concrete beams filled with demolished concrete lumps
|
Behavior of reinforced concrete beams filled with demolished concrete lumps
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bo Wu(South China Univ. of Technology); Zhe Xu(South China Univ. of Technology); Zhongguo John Ma(University of Tennessee Knoxville); Qiongxiang Liu(Shenzhen General Institute of Architectural Design and Research); Wei Liu(South China Univ. of Technology)"
] |
In the past decades, recycling use of demolished concrete was almost limited to the types of recycled coarse aggregate with a size of about 5-40 mm and recycled fine aggregate with a size of about 0-5 mm for concrete structures, and reuse of demolished concrete lumps (DCLs) with a size much larger than that of recycled aggregate, e.g., 50-300 mm, has been limited to roadbed, backfilling materials, or discarded to landfills. Treatment processes of DCLs are much simpler than those of recycled aggregate, leading to less cost and more energy-saving. In the future, the amount of demolished concrete is estimated to be much higher, so reuse of DCLs for concrete structures will become necessary. The objectives of this paper are to document the process of making reinforced concrete beams with DCLs, and to discuss the flexural and shear behaviors of those reinforced DCL beams through an experimental program, which includes three beams filled with DCLs and one conventional beam for investigating the flexural strengths and deformations, and 12 beams filled with DCLs and two conventional beams for investigating the shear strengths and deformations. The authors hope that the proposed concept offers another sustainable solution to the concrete industry.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595709
|
oai_dc
|
Active control of a nonlinear and hysteretic building structure with time delay
|
Active control of a nonlinear and hysteretic building structure with time delay
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kun Liu(Shanghai Jiaotong University); Long-Xiang Chen(Shanghai Jiaotong University); Guo-Ping Cai(Shanghai Jiaotong University)"
] |
Time delay inevitably exists in active control systems, and it may cause the degradation of control efficiency or instability of the systems. So time delay needs to be compensated in control design in order to eliminate its negative effect on control efficiency. Today time delay in linear systems has been more studied and some treating methods had been worked out. However, there are few treating methods for time delay in nonlinear systems. In this paper, an active controller for a nonlinear and hysteretic building structure with time delay is studied. The nonlinear and hysteretic behavior of the system is illustrated by the Bouc-Wen model. By specific transformation and augmentation of state parameters, the motion equation of the system with explicit time delay is transformed into the standard state space representation without any explicit time delay. Then the fourth-order Runge-Kutta method and instantaneous optimal control method are applied to the controller design with time delay. Finally, numerical simulations and comparisons of an eight-story building using the proposed time-delay controller are carried out. Simulation results indicate that the control performance will deteriorate if time delay is not taken into account in the control design. The simulations also prove the proposed time delay controller in this paper can not only effectively compensate time delay to get better control effectiveness, but also work well with both small and large time delay problems.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595705
|
oai_dc
|
Post-buckling analysis of Timoshenko beams with various boundary conditions under non-uniform thermal loading
|
Post-buckling analysis of Timoshenko beams with various boundary conditions under non-uniform thermal loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Turgut Kocaturk(Yildiz Technical University); Seref Doguscan Akbas(Yildiz Technical University)"
] |
This paper focuses on post-buckling analysis of Timoshenko beams with various boundary conditions subjected to a non-uniform thermal loading by using the total Lagrangian Timoshenko beam element approximation. Six types of support conditions for the beams are considered. The considered highly non-linear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. As far as the authors know, there is no study on the post-buckling analysis of Timoshenko beams under uniform and non-uniform thermal loading considering full geometric non-linearity investigated by using finite element method. The convergence studies are made and the obtained results are compared with the published results. In the study, the relationships between deflections, end rotational angles, end constraint forces, thermal buckling configuration, stress distributions through the thickness of the beams and temperature rising are illustrated in detail in postbuckling case.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595704
|
oai_dc
|
Bifurcations of non-semi-simple eigenvalues and the zero-order approximations of responses at critical points of Hopf bifurcation in nonlinear systems
|
Bifurcations of non-semi-simple eigenvalues and the zero-order approximations of responses at critical points of Hopf bifurcation in nonlinear systems
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yu Dong Chen(Jilin University); Chun Yan Pei(Jilin University); Su Huan Chen(Jilin University)"
] |
This paper deals with the bifurcations of non-semi-simple eigenvalues at critical point of Hopf bifurcation to understand the dynamic behavior of the system. By using the Puiseux expansion, the expression of the bifurcation of non-semi-simple eigenvalues and the corresponding topological structure in the parameter space are obtained. The zero-order approximate solutions in the vicinity of the critical points at which the multiple Hopf bifurcation may occur are developed. A numerical example, the flutter problem of an airfoil in simplified model, is given to illustrate the application of the proposed method.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595701
|
oai_dc
|
A method for evaluation of longitudinal joint connections of decked precast concrete girder bridges
|
A method for evaluation of longitudinal joint connections of decked precast concrete girder bridges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Matthew Z. Smith(Michigan Technological University); Yue Li(Michigan Technological University); William M. Bulleit(Michigan Technological University)"
] |
As bridge conditions in the United States continue to deteriorate, rapid bridge replacement procedures are needed. Decked precast prestressed concrete (DPPC) girders are used for rapid bridge construction because the bridge deck is precast with the girders eliminating the need for a cast-in-place slab. One of the concerns with using DPPC girders as a bridge construction option is the durability of the longitudinal joints between girders. The objectives of this paper were to propose a method to use a spring element modeling procedure for representing welded steel connector assemblies between adjacent girders in DPPC girder bridges, perform a preliminary study of bridge performance under multiple loading scenarios and bridge configurations, and discuss model flexibility for accommodating future field data for model verification. The spring elements have potential to represent the contribution of joint grout materials by altering the spring stiffness.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595707
|
oai_dc
|
An incompatible 3D solid element for structural analysis at elevated temperatures
|
An incompatible 3D solid element for structural analysis at elevated temperatures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xinmeng Yu(Harbin Institute of Technology); Xiaoxiong Zha(Harbin Institute of Technology); Zhaohui Huang(University of Sheffield)"
] |
The eight-node 3D solid element is one of the most extensively used elements in computational mechanics. This is due to its simple shape and easy of discretization. However, due to the parasitic shear locking, it should not be used to simulate the behaviour of structural members in bending dominant conditions. Previous researches have indicated that the introduction of incompatible mode into the displacement field of the solid element could significantly reduce the shear locking phenomenon. In this study, an incompatible mode eight-node solid element, which considers both geometric and material nonlinearities, is developed for modelling of structural members at elevated temperatures. An algorithm is developed to extend the state determination procedure at ambient temperature to elevated temperatures overcoming initially converged stress locking when the external load is kept constant. Numerical studies show that this incompatible element is superior in terms of convergence, mesh insensitivity and reducing shear locking. It is also showed that the solid element model developed in this paper can be used to model structural behaviour at both ambient and elevated temperatures.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595706
|
oai_dc
|
Vibration attenuation in periodic composite Timoshenko beams on Pasternak foundation
|
Vibration attenuation in periodic composite Timoshenko beams on Pasternak foundation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hong-Jun Xiang(Beijing Jiaotong University); Zhi-Fei Shi(Beijing Jiaotong University)"
] |
Periodic and quasi-periodic Timoshenko beams on Pasternak foundation are investigated using the differential quadrature method. Not only band gaps in the beams but also the dynamic response of them is analyzed. Numerical results show that vibration in periodic beams can be dramatically attenuated when the exciting frequency falls into band gaps. Different from the band structures of periodic beams without foundation, the so-called critical frequency was found because of the Pasternak foundation. Its physical meaning was explained in detail and a useful formula was given to calculate the critical frequency. Additionally, a comprehensive parameter study is conducted to highlight the influence of foundation modulus on the band gaps.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001595703
|
oai_dc
|
Modeling of triple concave friction pendulum bearings for seismic isolation of buildings
|
Modeling of triple concave friction pendulum bearings for seismic isolation of buildings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Muhammet Yurdakul(Bayburt University); Sevket Ates(Karadeniz Technical University)"
] |
Seismic isolated building structures are examined in this study. The triple concave friction pendulum (TCFP) is used as a seismic isolation system which is easy to be manufactured and enduring more than traditional seismic isolation systems. In the TCFP, take advantage of weight which pendulum carrying and it’s geometry in order to obtain desirable result of seismic isolation systems. These systems offer advantage to buildings which subject to severe earthquake. This is result of damping force of earthquake by means of their internal constructions, which consists of multiple surfaces. As the combinations of surfaces upon which sliding is occurring change, the stiffness and effective friction change accordingly. Additionally, the mentioned the TCFP is modeled as of a series arrangement of the three single concave friction pendulum (SCFP) bearings. A two dimensional- and eight- story of a building with and without isolation system are used in the time history analysis in order to investigate of the effectiveness of the seismic isolation systems on the buildings. Results are compared with each other to emphasize efficiency of the TCFP as a seismic isolation device against the other friction type isolation system like single and double concave surfaces. The values of the acceleration, floor displacement and isolator displacement obtained from the results by using different types of the isolation bearings are compared each other. As a result, the findings show that the TCFP bearings are more effective devices for isolation of the buildings against severe earthquakes.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572976
|
oai_dc
|
The effect of soil-structure interaction on inelastic displacement ratio of structures
|
The effect of soil-structure interaction on inelastic displacement ratio of structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Muberra Eser(Yildiz Technical University); Cem Aydemir(Yildiz Technical University)"
] |
In this study, inelastic displacement ratios and ductility demands are investigated for SDOF systems with period range of 0.1-3.0 s. with elastoplastic behavior considering soil structure interaction. Earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil are used in analyses. Soil structure interacting systems are modeled with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for inelastic displacement ratio of interacting system (C_R) as a function of structural period of interacting system (T),strength reduction factor (R) and period lengthening ratio (T/T). The proposed equation for C_R which takes the soil-structure interaction into account should be useful in estimating the inelastic deformation of existing structures with known lateral strength.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572981
|
oai_dc
|
Optimum amount of additive mass in scaling of operational mode shapes
|
Optimum amount of additive mass in scaling of operational mode shapes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M.M. Khatibi(Semnan University); M.R. Ashory(Semnan University); A.R. Albooyeh(Semnan University)"
] |
Recently, identification of modal parameters using the response only data has attracted considerable attention particularly where the classic modal testing methods is difficult to conduct. One drawback of the response only data, also known as Operational Modal Analysis (OMA), is that only the unscaled mode shapes can be obtained which restricts the applications of OMA. The Mass change method is a usual way to scale the operational mode shapes. In this article a new method is proposed to optimize the additive mass for scaling of the unscaled mode shapes from OMA for which a priori knowledge of the Finite Element model of structure is required. It is shown that the total error of the scaled mode shapes is minimized using the proposed method. The method is validated using a numerical case study of a beam. Moreover, the experimental results of a clamped-clamped beam demonstrate the applicability of the method.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572975
|
oai_dc
|
Matrix-based Chebyshev spectral approach to dynamic analysis of non-uniform Timoshenko beams
|
Matrix-based Chebyshev spectral approach to dynamic analysis of non-uniform Timoshenko beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"W.Y. Wang(National Central University); J.Y. Liao(Chung-Sun Institute of Science and Technology); L.W. Hourng(National Central University)"
] |
A Chebyshev spectral method (CSM) for the dynamic analysis of non-uniform Timoshenko beams under various boundary conditions and concentrated masses at their ends is proposed. The matrixbased Chebyshev spectral approach was used to construct the spectral differentiation matrix of the governing differential operator and its boundary conditions. A matrix condensation approach is crucially presented to impose boundary conditions involving the homogeneous Cauchy conditions and boundary conditions containing eigenvalues. By taking advantage of the standard powerful algorithms for solving matrix eigenvalue and generalized eigenvalue problems that are embodied in the MATLAB commands, chebfun and eigs, the modal parameters of non-uniform Timoshenko beams under various boundary conditions can be obtained from the eigensolutions of the corresponding linear differential operators. Some numerical examples are presented to compare the results herein with those obtained elsewhere , and to illustrate the accuracy and effectiveness of this method.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572971
|
oai_dc
|
Performance of tuned mass dampers against near-field earthquakes
|
Performance of tuned mass dampers against near-field earthquakes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"E. Matta(Turin Politechnic)"
] |
Passive tuned mass dampers (TMDs) efficiently suppress vibrations induced by quasistationary dynamic inputs, such as winds, sea waves or traffic loads, but may prove of little use against pulse-like excitations, such as near-field (NF) ground motions. The extent of such impairment is however controversial, partly due to the different evaluation criteria adopted within the literature, partly to the limited number of seismic records used in most investigations. In this study, three classical techniques and two new variants for designing a TMD on an SDOF structure are tested under 338 NF records from the PEER NGA database, including 156 records with forward-directivity features. Percentile response reduction spectra are introduced to statistically assess TMD performance, and TMD robustness is verified through Monte Carlo simulations. The methodology is extended to a variety of MDOF bending-type and shear-type frames, and simulated on a case study building structure recently constructed in Central Italy. Results offer an interesting insight into the performance of TMDs against NF earthquakes, ultimately showing that, if properly designed and sufficiently massive, TMDs are effective and robust even in the face of pulse-like ground motions. The two newly proposed design techniques are shown to generally outperform the classical ones.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572980
|
oai_dc
|
Evaluation of performance of eccentric braced frame with friction damper
|
Evaluation of performance of eccentric braced frame with friction damper
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J. Vaseghi Amiri(Babol University of Technology); B. Navayinia(Babol University of Technology); S. Navaei(Babol University of Technology)"
] |
Nonlinear dynamic analysis and evaluation of eccentric braced steel frames (EBF) equipped with friction damper (FD) is studied in this research. Previous studies about assessment of seismic performance of steel braced frame with FD have been generally limited to installing this device in confluence of cross in concentrically braced frame such chevron and x-bracing. Investigation is carried out with three types of steel frames namely 5, 10 and 15 storeys, representing the short, medium and high structures respectively in series of nonlinear dynamic analysis and 10 slip force values subjected to three different earthquake records. The proper place of FD, rather than providing them at all level is also studied in 15 storey frame. Four dimensionless indices namely roof displacement, base shear, dissipated energy and relative performance index (RPI) are determined in about 100 nonlinear dynamic analyses. Then average values of maximum roof displacement, base shear, energy dissipated and storey drift under three records for both EBF and EBF equipped with friction damper are obtained. The result indicates that FD reduces the response compared to EBF and is more efficient than EBF for taller storey frames.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572972
|
oai_dc
|
Stability limit state design of box sections supporting mining and process facilities
|
Stability limit state design of box sections supporting mining and process facilities
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Osama Bedair(Technip Corporation)"
] |
The design of box girders requires the determinations the buckling stress of the flange and the webs. Existing design equations available in codes of practice ignore the interactions between the box girder components. The paper illustrates the influence of the geometric interaction on the buckling stress of box girders. Generalized equations are first derived in terms of the web the flange geometric properties. Industrial examples are then presented showing the variation of the flange buckling stress for various stiffening configurations. The influence of the flange/web proportions on the buckling stress of box girder components is also highlighted. It is shown that buckling strength of the flange is largely affected by the restraints imposed by the webs or attached diaphragms. Graphs are presented showing various limiting states of box girders. These graphs are useful to use in practice in order to achieve economical and efficient design of box girders and rationally predict local buckling stress.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572974
|
oai_dc
|
Equivalent stiffness method for nonlinear analysis of stay cables
|
Equivalent stiffness method for nonlinear analysis of stay cables
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G.Y. Xia(Changsha University of Science and Technology); C.S. Cai(Louisiana State University)"
] |
In the famous equivalent elasticity modulus method proposed by Ernst for the geometrical nonlinear analysis of stay cables, the cable shape was assumed as a parabolic curve, and only a part of the gravity load normal to the chord was taken into account with the other part of gravity load parallel to the chord being ignored. Using the actual catenary curve and considering the entire gravity load of stay cables, the present study has derived the equivalent stiffness method to analyze the sag effect of stay cables in cable-stayed bridges. The derived equivalent stiffness can be degenerated into Ernst’s equivalent elasticity modulus method with some approximations. Therefore, the Ernst’s method is a special and approximate formulation of the present method. The derived equivalent stiffness provides a theoretical explanation for the famous Ernst’s formula.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001572978
|
oai_dc
|
Dynamic analysis of structures in frequency domain by a new set of Ritz vectors
|
Dynamic analysis of structures in frequency domain by a new set of Ritz vectors
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Aliasghar Arjmandi(Amirkabir University of Technology); Vahid Lotfi(Amirkabir University of Technology)"
] |
The accurate dynamic analysis of structures is usually performed by a fine finite element discretization with very large number of degrees of freedom. Apart from modal analysis, one can reduce the number of final equations by assuming the deformed shape of the structure as a linear combination of independent Ritz vectors. The efficiency of this method relies heavily on the vectors selected. In this paper, a new set of Ritz vectors is proposed. It is primarily proved that these vectors are linearly independent. Subsequently, various two and three-dimensional examples are analyzed based on the proposed method. In each case, the results are compared with the ones obtained based on usual Ritz and modal analysis methods. It is finally concluded that the proposed method is very effective and efficient method for dynamic analysis of structures in frequency domain.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576375
|
oai_dc
|
Fragility analysis of R/C frame buildings based on different types of hysteretic model
|
Fragility analysis of R/C frame buildings based on different types of hysteretic model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Muzaffer Borekci(Yildiz Technical University); Murat S. Kirçil(Yildiz Technical University)"
] |
Estimation of damage probability of buildings under a future earthquake is an essential issue to ensure the seismic reliability. Fragility curves are useful tools for showing the probability of structural damage due to earthquakes as a function of ground motion indices. The purpose of this study is to compare the damage probability of R/C buildings with low and high level of strength and ductility through fragility analysis. Two different types of sample buildings have been considered which represent the building types mentioned above. The first one was designed according to TEC-2007 and the latter was designed according to TEC-1975. The pushover curves of sample buildings were obtained via pushover analyses. Using 60 ground motion records, nonlinear time-history analyses of equivalent single degree of freedom systems were performed using bilinear hysteretic model and peak-oriented hysteretic model with stiffness – strength deterioration for each scaled elastic spectral displacement. The damage measure is maximum inter-story drift ratio and each performance level considered in this study has an assumed limit value of damage measure. Discrete damage probabilities were calculated using statistical methods for each considered performance level and elastic spectral displacement. Consequently, continuous fragility curves have been constructed based on the lognormal distribution assumption. Furthermore, the effect of hysteresis model parameters on the damage probability is investigated.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576379
|
oai_dc
|
Vibration analysis of wave motion in micropolar thermoviscoelastic plate
|
Vibration analysis of wave motion in micropolar thermoviscoelastic plate
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rajneesh Kumar(Kurukshetra University); Geeta Partap(Ambedkar National Institute of Technology)"
] |
The aim of the present article is to study the micropolar thermoelastic interactions in an infinite Kelvin-Voigt type viscoelastic thermally conducting plate. The coupled dynamic thermoelasticity and generalized theories of thermoelasticity, namely, Lord and Shulman’s and Green and Lindsay’s are employed by assuming the mechanical behaviour as dynamic to study the problem. The model has been simplified by using Helmholtz decomposition technique and the resulting equations have been solved by using variable separable method to obtain the secular equations in isolated mathematical conditions for homogeneous isotropic micropolar thermo-viscoelastic plate for symmetric and skew-symmetric wave modes. The dispersion curves, attenuation coefficients, amplitudes of stresses and temperature distribution for symmetric and skew-symmetric modes are computed numerically and presented graphically for a magnesium crystal.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576378
|
oai_dc
|
Experimental investigation on the buckling of thin cylindrical shells with two-stepwise variable thickness under external pressure
|
Experimental investigation on the buckling of thin cylindrical shells with two-stepwise variable thickness under external pressure
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sirous Aghajari(Sahand University of Technology); Hossein Showkati(Urmia University); Karim Abedi(Sahand University of Technology)"
] |
The buckling capacity of the cylindrical shells depends on two geometric ratios of L/R and R/t. However the effect of thickness variation on the behavior of the shells is more complicated and the buckling strength of them is sensitive to the magnitude and shape of geometric imperfections. In this paper the effects of thickness variation and geometric imperfections on the buckling and postbuckling behavior of cylindrical shells are experimentally investigated. The obtained results are presented under the effect of uniform lateral pressure. It is found in this investigation that the buckling mode can be generated in the whole length of the shell, if the thickness variation is low.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576374
|
oai_dc
|
An edge-based smoothed finite element method for adaptive analysis
|
An edge-based smoothed finite element method for adaptive analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"L. Chen(National University of Singapore); J. Zhang(National University of Singapore); K.Y. Zeng(National University of Singapore); P.G. Jiao(Shandong University)"
] |
An efficient edge-based smoothed finite element method (ES-FEM) has been recently developed for solving solid mechanics problems. The ES-FEM uses triangular elements that can be generated easily for complicated domains. In this paper, the complexity study of the ES-FEM based on triangular elements is conducted in detail, which confirms the ES-FEM produces higher computational efficiency compared to the FEM. Therefore, the ES-FEM offers an excellent platform for adaptive analysis, and this paper presents an efficient adaptive procedure based on the ES-FEM. A smoothing domain based energy (SDE) error estimate is first devised making use of the features of the ES-FEM. The present error estimate differs from the conventional approaches and evaluates error based on smoothing domains used in the ES-FEM. A local refinement technique based on the Delaunay algorithm is then implemented to achieve high efficiency in the mesh refinement. In this refinement technique, each node is assigned a scaling factor to control the local nodal density, and refinement of the neighborhood of a node is accomplished simply by adjusting its scaling factor. Intensive numerical studies, including an actual engineering problem of an automobile part, show that the proposed adaptive procedure is effective and efficient in producing solutions of desired accuracy.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576373
|
oai_dc
|
Detection of a concentrated damage in a parabolic arch by measured static displacements
|
Detection of a concentrated damage in a parabolic arch by measured static displacements
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Annalisa Greco(University of Catania); Annamaria Pau(La Sapienza University of Rome)"
] |
The present paper deals with the identification of a concentrated damage in an elastic parabolic arch through the minimization of an objective function which measures the differences between numerical and experimental values of static displacements. The damage consists in a notch that reduces the height of the cross section at a given abscissa and therefore causes a variation in the flexural stiffness of the structure. The analytical values of static displacements due to applied loads are calculated by means of the principle of virtual work for both the undamaged and damaged arch. First, pseudo-experimental data are used to study the inverse problem and investigate whether a unique solution can occur or not. Various damage intensities are considered to assess the reliability of the identification procedure. Then, the identification procedure is applied to an experimental case, where displacements are measured on a prototype arch. The identified values of damage parameters, i.e., location and intensity, are compared to those obtained by means of a dynamic identification technique performed on the same structure.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576377
|
oai_dc
|
Time-dependent properties of lightweight concrete using sedimentary lightweight aggregate and its application in prestressed concrete beams
|
Time-dependent properties of lightweight concrete using sedimentary lightweight aggregate and its application in prestressed concrete beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"How-Ji Chen(National Chung-Hsing University); Wen-Po Tsai(National Chung-Hsing University); Chao-Wei Tang(Cheng-Shiu University); Te-Hung Liu(National Chung-Hsing University)"
] |
We have developed a lightweight aggregate (LWA) concrete made by expanding fine sediments dredged from the Shihmen Reservoir (Taiwan) with high heat. In this study, the performance of the concrete and of prestressed concrete beams made of the sedimentary LWA were tested and compared with those made of normal-weight concrete (NC). The test results show that the lightweight concrete (LWAC) exhibited comparable time-dependent properties (i.e., compressive strength, elastic modulus, drying shrinkage, and creep) as compared with the NC samples. In addition, the LWAC beams exhibited a smaller percentage of prestress loss compared with the NC beams. Moreover, on average, the LWAC beams could resist loading up to 96% of that of the NC beams, and the experimental strengths were greater than the nominal strengths calculated by the ACI Code method. This investigation thus established that sedimentary LWA can be recommended for structural concrete applications.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576376
|
oai_dc
|
A hybrid algorithm based on EEMD and EMD for multi-mode signal processing
|
A hybrid algorithm based on EEMD and EMD for multi-mode signal processing
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jeng-Wen Lin(Feng Chia University)"
] |
This paper presents an efficient version of Hilbert-Huang transform for nonlinear nonstationary systems analyses. An ensemble empirical mode decomposition (EEMD) is introduced to alleviate the problem of mode mixing between intrinsic mode functions (IMFs) decomposed by EMD. Yet the problem has not been fully resolved when a signal of a similar scale resides in different IMF components. Instead of using a trial and error method to select the “best” outcome generated by EEMD, a hybrid algorithm based on EEMD and EMD is proposed for multi-mode signal processing. The developed approach comprises the steps from a bandpass filter design for regrouping modes of the IMFs obtained from EEMD, to the mode extraction using EMD, and to the assessment of each mode in the marginal spectrum. A simulated two-mode signal is tested to demonstrate the efficiency and robustness of the approach, showing average relative errors all equal to 1.46% for various noise levels added to the signal. The developed approach is also applied to a real bridge structure, showing more reliable results than the pure EMD. Discussions on the mode determination are offered to explain the connection between modegrouping form on the one hand, and mode-grouping performance on the other.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001576380
|
oai_dc
|
Probabilistic study of the influence of ground motion variables on response spectra
|
Probabilistic study of the influence of ground motion variables on response spectra
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Azad Yazdani(University of Kurdistan); Tsuyoshi Takada(The University of Tokyo)"
] |
Response spectra of earthquake ground motions are important in the earthquake-resistant design and reliability analysis of structures. The formulation of the response spectrum in the frequency domain efficiently computes and evaluates the stochastic response spectrum. The frequency information of the excitation can be described using different functional forms. The shapes of the calculated response spectra of the excitation show strong magnitude and site dependency, but weak distance dependency. In this paper, to compare the effect of the earthquake ground motion variables, the contribution of these sources of variability to the response spectrum’s uncertainty is calculated by using a stochastic analysis. The analytical results show that earthquake source factors and soil condition variables are the main sources of uncertainty in the response spectra, while path variables, such as distance, anelastic attenuation and upper crust attenuation, have relatively little effect. The presented formulation of dynamic structural response in frequency domain based only on the frequency information of the excitation can provide an important basis for the structural analysis in some location that lacks strong motion records.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001596614
|
oai_dc
|
Free vibration of an axially functionally graded pile with pinned ends embedded in Winkler-Pasternak elastic medium
|
Free vibration of an axially functionally graded pile with pinned ends embedded in Winkler-Pasternak elastic medium
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dogan Çetin(Yildiz Technical University); Mesut Simsek(Yildiz Technical University)"
] |
In the present study, free vibration of an axially functionally graded (AFG) pile embedded in Winkler-Pasternak elastic foundation is analyzed within the framework of the Euler-Bernoulli beam theory. The material properties of the pile vary continuously in the axial direction according to the power-law form. The frequency equation is obtained by using Lagrange’s equations. The unknown functions denoting the transverse deflections of the AFG pile is expressed in modal form. In this study, the effects of material variations, the parameters of the elastic foundation on the fundamental frequencies are examined. It is believed that the tabulated results will be a reference with which other researchers can compare their results.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001596610
|
oai_dc
|
Shake-table responses of a low-rise RC building model having irregularities at first story
|
Shake-table responses of a low-rise RC building model having irregularities at first story
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"이한선(고려대학교); 정동욱(OPUS PEARL Co.); 이경보(고려대학교); 김희철(경희대학교); 이기학(세종대학교)"
] |
This paper presents the seismic responses of a 1:5-scale five-story reinforced concrete building model, which represents a residential apartment building that has a high irregularity of weak story, soft story, and torsion simultaneously at the ground story. The model was subjected to a series of uni- and bi-directional earthquake simulation tests. Analysis of the test results leads to the following conclusions: (1) The model survived the table excitations simulating the design earthquake with the PGA of 0.187 g without any significant damages, though it was not designed against earthquakes; (2) The fundamental mode was the torsion mode. The second and third orthogonal translational modes acted independently while the torsion mode showed a strong correlation with the predominant translational mode; (3) After a significant excursion into inelastic behavior, this correlation disappeared and the maximum torsion and torsion deformation remained almost constant regardless of the intensity of the two orthogonal excitations; And, (4) the lateral resistance and stiffness of the critical columns and wall increased or decreased significantly with the large variation of acting axial forces caused by the high bidirectional overturning moments and rocking phenomena under the bi-directional excitations.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001596612
|
oai_dc
|
Concurrent flexural strength and deformability design of high-performance concrete beams
|
Concurrent flexural strength and deformability design of high-performance concrete beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J.C.M. Ho(The University of Hong Kong); K.J.H. Zhou(The University of Hong Kong)"
] |
In the design of earthquake resistant reinforced concrete (RC) structures, both flexural strength and deformability need to be considered. However, in almost all existing RC design codes, the design of flexural strength and deformability of RC beams are separated and independent on each other.
Therefore, the pros and cons of using high-performance materials on the flexural performance of RC beams are not revealed. From the theoretical results obtained in a previous study on flexural deformability of RC beams, it is seen that the critical design factors such as degree of reinforcement, concrete/steel yield strength and confining pressure would simultaneously affect the flexural strength and deformability. To study the effects of these factors, the previous theoretical results are presented in various charts plotting flexural strength against deformability. Using these charts, a "concurrent flexural strength and deformability design" that would allow structural engineers to consider simultaneously both strength and deformability requirements is developed. For application in real construction practice where concrete strength is usually prescribed, a simpler method of determining the maximum and minimum limits of degree of reinforcement for a particular pair of strength and deformability demand is proposed. Numerical examples are presented to illustrate the application of both design methods.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001596604
|
oai_dc
|
Experimental study on Chinese ancient timber-frame building by shaking table test
|
Experimental study on Chinese ancient timber-frame building by shaking table test
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xi-cheng Zhang(Xi’an University of Architecture and Technology); Jian-yang Xue(Xi’an University of Architecture and Technology); Hong-tie Zhao(Xi’an University of Architecture and Technology); Yan Sui(Xi’an University of Architecture and Technology)"
] |
A one-story, wooden-frame, intermediate-bay model with Dou-Gon designed according to the Building Standards of the Song Dynasty (A.D.960-1279), was tested on a unidirectional shaking table. The main objectives of this experimental study were to investigate the seismic performance of Chinese historic wooden structure under various base input intensities. El Centro wave (N-S), Taft wave and Lanzhou wave were selected as input excitations. 27 seismic geophones were instrumented to measure the real-time displacement, velocity and acceleration respectively. Dynamic characteristics, failure mode and hysteretic energy dissipation performance of the model are analyzed. Test results indicate that the nature period and damping ratio of the model increase with the increasing magnitude of earthquake excitation. The nature period of the model is within 0.5~0.6 s, the damping ratio is 3~4%. The maximum acceleration dynamic magnification factor is less than 1 and decreases as the input seismic power increases. The frictional slippage of Dou-Gon layers (corbel brackets) between beams and plates dissipates a certain amount of seismic energy, and so does the slippage between posts and plinths. The mortise-tenon joint of the timber frame dissipates most of the seismic energy. Therefore, it plays a significant part in shock absorption and isolation.
|
토목공학
| null |
kci_detailed_000075.xml
|
|||
ART001596609
|
oai_dc
|
A study on transverse vibration characteristics of a sandwich plate with asymmetrical faces
|
A study on transverse vibration characteristics of a sandwich plate with asymmetrical faces
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"안남식(Sejong University); Kangsu Lee(Green and Industrial Technology Center)"
] |
Sandwich elements have high flexural rigidity and high strength per density. They also have excellent anti-vibration and anti-noise characteristics. Therefore, they are used for structures of airplanes and high speed ships that must be light, as well as strong. In this paper, the Reissner-Mindlin’s plate theory is studied from a Hamilton’s principle point of view. This theory is modified to include the influence of shear deformation and rotary inertia, and the equation of motion is derived using energy relationships. The theory is applied to a rectangular sandwich model which has isotropic, asymmetrical faces and an isotropic core. Investigations are conducted for five different plate thicknesses. These plates are identical to the sandwich plates currently used in various structural elements of surface effect ships (SES). The boundary conditions are set to simple supports and fixed supports. The elastic and shear moduli are obtained from the four-point bending tests on the sandwich beams.
|
토목공학
| null |
kci_detailed_000076.xml
|
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