src/Mod/Fem/femsolver/calculix/write_constraint_electrostatic.py

# SPDX-License-Identifier: LGPL-2.1-or-later

# ***************************************************************************
# *   Copyright (c) 2025 Mario Passaglia <mpassaglia[at]cbc.uba.ar>         *
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__title__ = "FreeCAD FEM calculix constraint electrostatic"
__author__ = "Mario Passaglia"
__url__ = "https://www.freecad.org"

import FreeCAD


def get_analysis_types():
    return ["electromagnetic"]


def get_sets_name():
    return "constraints_electrostaticpotential_node_sets"


def get_constraint_title():
    return "Fixed electrostatic constraint applied"


def write_meshdata_constraint(f, femobj, pot_obj, ccxwriter):

    if ccxwriter.solver_obj.ElectromagneticMode != "electrostatic":
        return

    if femobj["Object"].BoundaryCondition == "Dirichlet":
        f.write(f"*NSET,NSET={pot_obj.Name}\n")
        for n in femobj["Nodes"]:
            f.write(f"{n},\n")


def get_before_write_meshdata_constraint():
    return ""


def get_after_write_meshdata_constraint():
    return ""


def get_before_write_constraint():
    return ""


def get_after_write_constraint():
    return ""


def write_constraint(f, femobj, pot_obj, ccxwriter):

    if ccxwriter.solver_obj.ElectromagneticMode != "electrostatic":
        return

    # floats read from ccx should use {:.13G}, see comment in writer module
    if pot_obj.BoundaryCondition == "Dirichlet":
        f.write("*BOUNDARY\n")
        f.write("{},11,11,{:.13G}\n".format(pot_obj.Name, pot_obj.Potential.getValueAs("mV").Value))
    elif pot_obj.BoundaryCondition == "Neumann":
        density = pot_obj.ElectricFluxDensity.getValueAs("C/mm^2").Value
        # check internal interface
        internal = _check_shared_interface(pot_obj)
        for feat, surf, is_sub_el in femobj["ElectricFluxFaces"]:
            f.write("** {0.Name}.{1[0]}\n".format(*feat))
            f.write("*DFLUX\n")
            d = density
            if feat in internal:
                d = density / 2
            for face, fno in surf:
                f.write("{},S{},{:.13G}\n".format(face, fno, d))

    f.write("\n")


def _check_shared_interface(pot_obj):
    """
    Check if reference is internal shared subshape
    For example, shared face in compsolid
    """
    internal = []
    for o, sub in pot_obj.References:
        for elem in sub:
            found = []
            elem_i = o.getSubObject(elem)
            if elem_i.ShapeType == "Face":
                for s in o.Shape.Solids:
                    found.append(any([q.isSame(elem_i) for q in s.Faces]))
                if sum(found) > 1:
                    internal.append((o, (elem,)))

            if elem_i.ShapeType == "Edge":
                for s in o.Shape.Faces:
                    found.append(any([q.isSame(elem_i) for q in s.Edges]))
                if sum(found) > 1:
                    internal.append((o, (elem,)))

    return internal