Good day!!
I have a model that is based on a mixed mesh of beams and
plates. I am trying to assemble my Timoshenko beam torsional
contribution on the beam region of the mesh.
When the mesh was uniform, with beams only, it worked fine,
but when I added the plates (even though I assemble only the
beam region) I'm starting to get dimension mismatches like
this one:
Trace 1: Imported mesh with 128 beam and 96 plate elements
Def TangentProjectionGrad_Test_rotation:=(Grad_Test_rotation .
Normalized(element_K)) . Normalized(element_K)
--------------------------------------------------------------------------------------^
Dot product of expressions of different sizes (2 != 3).
Kind request to advise.
Below I created a minimal working code with two GMSH meshes
(beams only and a mixed mesh with beams and plates).
#include <catch2/catch.hpp>
#include <getfem/getfem_import.h>
#include <getfem/getfem_models.h>
std::string tensorTangentProjectionOnFrame(getfem::ga_workspace &workspace, const std::string &name)
{
auto tangentName = "TangentProjection" + name;
workspace.add_macro(tangentName, "(" + name + " . Normalized(element_K)) . Normalized(element_K)");
return tangentName;
}
TEST_CASE("assembly with mixed meshes")
{
auto meshName = "tower_with_floors.msh"; //mixed beam/plates mesh, doesn't work
//auto meshName = "tower_dense.msh"; //beams only, works
getfem::mesh mesh;
std::map<std::string, bgeot::size_type> regionMap;
std::set<bgeot::size_type> lowerDimConvexes;
getfem::import_mesh_gmsh(meshName, mesh, true, &lowerDimConvexes,
®ionMap, false, nullptr, false);
auto shellRegion = getfem::mesh_region::free_region_id(mesh);
auto frameRegion = shellRegion + 1;
size_t nFrames = 0;
size_t nShells = 0;
for (auto &&cv : dal::bv_iterable_c{mesh.convex_index()})
{
const auto pGeoTrans = mesh.trans_of_convex(cv);
if (pGeoTrans->dim() == 1)
{
mesh.region(frameRegion).add(cv);
++nFrames;
}
else if (pGeoTrans->dim() == 2)
{
mesh.region(shellRegion).add(cv);
++nShells;
}
}
GMM_SIMPLE_TRACE1("Imported mesh with " << nFrames << " beam and "
<< nShells << " plate elements");
getfem::mesh_fem mf(mesh);
mf.set_qdim(3);
mf.set_classical_finite_element(2);
getfem::mesh_im mim(mesh);
mim.set_integration_method(4);
getfem::model model;
model.add_fem_variable("rotation", mf);
model.add_initialized_scalar_data("G", 10e6); //shear modulus
model.add_initialized_scalar_data("It", 1); //torsional moment of inertia
//Assembling Timoshenko torsional component on a frame region
getfem::ga_workspace workspace(model);
workspace.add_macro("Torsion", tensorTangentProjectionOnFrame(workspace, "Grad_rotation"));
workspace.add_macro("VarTorsion", tensorTangentProjectionOnFrame(workspace, "Grad_Test_rotation"));
workspace.add_expression("G * It * VarTorsion * Torsion", mim, frameRegion);
REQUIRE_NOTHROW(workspace.assembly(1));
}
Best regards,
Andriy