{
  "license": "ODC-By v1.0",
  "license_url": "https://opendatacommons.org/licenses/by/1-0/",
  "dataset": "DeepJEB++ TRELLIS-generated jet-engine bracket surface-FEA dataset",
  "version": "1.0",
  "date": "2026-06-07",
  "n_cases": 15360,
  "case_id_format": "<base>-<sub>-diag_xz_mm_IS<aug>  (shared by mesh / field / BC / label row)",
  "units": {
    "length": "mm",
    "displacement": "mm",
    "force": "N",
    "moment": "N*mm",
    "stress": "MPa",
    "mass": "g",
    "volume": "mm^3"
  },
  "material": {
    "name": "Ti-6Al-4V",
    "model": "linear isotropic elasticity (static)",
    "youngs_modulus_MPa": 113800.0,
    "poisson_ratio": 0.342,
    "density_g_per_mm3": 0.00443
  },
  "load_cases": [
    {
      "name": "ver",
      "type": "force",
      "direction": [
        0.0,
        0.0,
        1.0
      ],
      "magnitude": 35600.0,
      "unit": "N"
    },
    {
      "name": "hor",
      "type": "force",
      "direction": [
        -1.0,
        0.0,
        0.0
      ],
      "magnitude": 37800.0,
      "unit": "N"
    },
    {
      "name": "dia",
      "type": "force",
      "direction": [
        -0.669,
        0.0,
        0.743
      ],
      "magnitude": 42300.0,
      "unit": "N"
    },
    {
      "name": "tor",
      "type": "moment",
      "direction": [
        0.0,
        1.0,
        0.0
      ],
      "magnitude": 565000.0,
      "unit": "N*mm"
    }
  ],
  "boundary_conditions": {
    "dirichlet": "4 bolt holes clamped (u = 0)",
    "neumann": "total traction applied on the lug/clevis bore, shared equally over lug nodes",
    "interface_detection": "deterministic 4-bolt + loaded-clevis detection (paper 3.4.1), Umeyama-registered to the GT frame",
    "index_frame": "all BC node indices reference fields/<case>.npz surface_points (25k FEM mesh, ~24.9k verts), NOT the native 50k .obj"
  },
  "mesh": {
    "native_surface": "meshes ~50k verts (.obj), source output_v2/_tri",
    "fem_surface": "decimated to FEM_TARGET_VERTS=25000, pymeshfix-cleaned",
    "volume": "tetgen tetrahedralization, switches pq1.2/10Y",
    "note_robust_6": "6 complex cases (187-384-IS06, 217-136-IS09, 384-123-IS00, 384-136-IS18, 384-279-IS13, 384-548-IS08) used a robust decimation (pymeshfix-before-decimate) to avoid tetgen self-intersection; same 25k target."
  },
  "mass": {
    "formula": "mass_g = density_g_per_mm3 * enclosed_volume_mm3",
    "volume_source": "pymeshfix-watertight enclosed volume of the registered native ~50k mesh (full resolution; more accurate than the 25k FEM tet volume)",
    "stats_g": {
      "min": 83.6,
      "median": 233.2,
      "max": 1500.7
    }
  },
  "layout": {
    "1_surface_meshes/": "15,360 input surface meshes (.obj, native ~50k verts)",
    "2_boundary_conditions/": "15,360 BC (.npz): bolt_idx, bolt_holes(0-3), lug_idx, n_surface, R, jaccard_bolt, frame",
    "3_fea_fields/": "15,360 surface FEA fields (.npz): surface_points, surface_faces, R, cov_min, dXZ, and per load {ver,hor,dia,tor}_U, _vm, _maxu, _p95vm",
    "deepjebpp_labels.csv": "per-case scalar labels (15,360 rows): case, mass_g, vol_mm3, cov_min, dXZ, R, {load}_maxu, {load}_p95vm, {load}_maxvm",
    "metadata.json": "this file",
    "README.txt": "human-readable spec"
  },
  "field_npz_keys": {
    "surface_points": "(N,3) float32 mm",
    "surface_faces": "(M,3) int32",
    "R": "float lug bore radius mm",
    "cov_min": "float lug-detection diagnostic",
    "dXZ": "float lug-detection diagnostic",
    "<load>_U": "(N,3) float32 surface displacement mm",
    "<load>_vm": "(N,) float32 surface von Mises MPa",
    "<load>_maxu": "float max displacement magnitude over volume mm",
    "<load>_p95vm": "float 95th-percentile von Mises over volume nodes MPa"
  },
  "notes": {
    "mass_vs_cad_validation": "The paper's 'R^2=0.9999 vs CAD' mass validation refers to the volume->mass pipeline checked against CAD reference masses (SimJEB GT, which has CAD). Generated TRELLIS brackets have no CAD counterpart, so that validation is not reproduced per-case here; the same deterministic volume pipeline is used.",
    "all_at_25k": "All 15,360 field/BC entries are at the same 25k FEM mesh density (consistent labels)."
  }
}