Hello again,
I've been working diligently to understand as to why I receive "level is
zero" error. I'd appreciate any code review and advice. The purpose is
just to demonstrate basic xfem behavior in the compact specimen mesh
(v4.gmsh.msh).
Thank you,
Andy
/**@file compact.cc
@brief compact specimen problem.
*/
#include "getfem/getfem_model_solvers.h"
#include "getfem/getfem_export.h"
#include "gmm/gmm.h"
#include "getfem/getfem_import.h"
#include "getfem/getfem_assembling.h"
#include "getfem/getfem_generic_assembly.h"
#include "getfem/getfem_mesh_im_level_set.h"
#include "getfem/getfem_mesh_fem_level_set.h"
#include "getfem/getfem_mesh_fem_product.h"
#include "getfem/getfem_mesh_fem_global_function.h"
#include "getfem/getfem_mesh_fem_sum.h"
#include <string>
#include <cstring>
#include <sstream>
#include <iostream>
using std::endl; using std::cout; using std::cerr;
using std::ends; using std::cin;
using bgeot::size_type;
using bgeot::base_node;
using bgeot::base_small_vector;
typedef getfem::model_real_plain_vector plain_vector;
using bgeot::scalar_type; /* = double */
int main(void) {
double E = 21E6; // Young Modulus (N/cm^2)
double nu = 0.3; // Poisson ratio
double clambda = E*nu/((1+nu)*(1-2*nu));
double cmu = E/(2*(1+nu));
double clambdastar = 2*clambda*cmu/(clambda+2*cmu);
double residual = 1E-9;
getfem::mesh mesh;
getfem::import_mesh("gmsh:v4.gmsh.msh",mesh);
getfem::mesh_fem mf(mesh);
getfem::level_set ls(mesh);
getfem::mesh_level_set mls(mesh);
mls.add_level_set(ls);
std::vector<getfem::pglobal_function> vfunc(4);
for (unsigned j=0; j < 4; ++j) {
getfem::crack_singular_xy_function *s =
new getfem::crack_singular_xy_function(j);
vfunc[j] = getfem::global_function_on_level_set(ls, *s);
}
getfem::mesh_fem_level_set mfls(mls, mf);
getfem::mesh_fem_global_function mf_sing(mesh);
mf_sing.set_functions(vfunc);
getfem::mesh_fem_sum mfu(mesh);
mfu.set_mesh_fems(mf_sing, mfls);
getfem::mesh_im_level_set mim(mls,
getfem::mesh_im_level_set::INTEGRATE_ALL,
getfem::int_method_descriptor("IM_TETRAHEDRON(6)"),
getfem::int_method_descriptor("IM_QUASI_POLAR(IM_TETRAHEDRON(8), 2)"));
mls.adapt();
mfls.adapt();
mim.adapt();
getfem::mesh_fem mfvm(mesh, 1);
mfvm.set_classical_discontinuous_finite_element(1);
getfem::model md;
md.add_fem_variable("u", mfu);
md.add_initialized_scalar_data("cmu", cmu);
md.add_initialized_scalar_data("clambdastar", clambdastar);
getfem::add_isotropic_linearized_elasticity_brick
(md, mim, "u", "clambdastar", "cmu");
getfem::add_normal_Dirichlet_condition_with_multipliers(md,mim,"u", 1, 109);
getfem::add_source_term_brick(md,mim,"u","[0,1640,0]", 108);
gmm::iteration iter(residual, 1, 50);
getfem::standard_solve(md, iter,
getfem::rselect_linear_solver(md,"superlu"));
plain_vector U(mfu.nb_dof()); gmm::copy(md.real_variable("u"), U);
plain_vector VM(mfvm.nb_dof());
getfem::compute_isotropic_linearized_Von_Mises_or_Tresca
(md, "u", "clamabdastar", "cmu", mfvm, VM, false);
getfem::vtk_export exp2("d_w_vm.vtk", false);
exp2.exporting(mfu);
exp2.write_point_data(mfu, U, "displacement");
exp2.write_point_data(mfvm, VM, "Von Mises stress");
}
On Mon, Jun 13, 2016 at 7:03 AM, Yves Renard <[email protected]>
wrote:
>
> Dear Andrew,
>
> This message appear when the level_set function is identically zero on an
> element (the level set function have to be "close" to a signed distance).
> Are you sure you initialized your level-set function with a correct value ?
>
> Best regards,
>
> Yves.
>
>
> Le 12/06/2016 23:33, Andrew Roberts a écrit :
>
> Working to demo 3d XFEM crack propagation of a steel compact specimen
> top-half (gmsh import).
>
> It compiles fine but the executable throws a "level is zero" error which
> I'm uncertain of the source of this error. Code attached below.
>
> /**@file compact.cc
>> @brief three-dimensional XFEM crack propagation.
>>
>> */
>>
>> #include "getfem/getfem_model_solvers.h"
>> #include "getfem/getfem_export.h"
>> #include "gmm/gmm.h"
>> #include "getfem/getfem_import.h"
>> #include "getfem/getfem_assembling.h"
>> #include "getfem/getfem_generic_assembly.h"
>> #include "getfem/getfem_mesh_im_level_set.h"
>> #include "getfem/getfem_mesh_fem_level_set.h"
>> #include "getfem/getfem_mesh_fem_product.h"
>> #include "getfem/getfem_mesh_fem_global_function.h"
>> #include "getfem/getfem_mesh_fem_sum.h"
>> #include <string>
>> #include <cstring>
>> #include <sstream>
>> #include <iostream>
>>
>> using std::endl; using std::cout; using std::cerr;
>> using std::ends; using std::cin;
>>
>> using bgeot::size_type;
>> using bgeot::base_node;
>> using bgeot::base_small_vector;
>> typedef getfem::model_real_plain_vector plain_vector;
>>
>>
>> using bgeot::scalar_type; /* = double */
>>
>> int main(void) {
>>
>> double E = 21E6; // Young Modulus (N/cm^2)
>> double nu = 0.3; // Poisson ratio
>> double clambda = E*nu/((1+nu)*(1-2*nu));
>> double cmu = E/(2*(1+nu));
>> double clambdastar = 2*clambda*cmu/(clambda+2*cmu);
>>
>> double residual = 1E-9;
>>
>> getfem::mesh mesh;
>> getfem::import_mesh("gmsh:v4.gmsh.msh",mesh);
>>
>>
>> getfem::mesh_fem mf(mesh, 3);
>>
>> getfem::mesh_fem mfvm(mesh, 1);
>>
>> mf.set_finite_element(mesh.convex_index(),
>> getfem::fem_descriptor("FEM_PK(3,2)"));
>>
>> mfvm.set_classical_discontinuous_finite_element(1);
>>
>> getfem::level_set ls(mesh, 1, true);
>> getfem::mesh_level_set mls(mesh);
>> mls.add_level_set(ls);
>> mls.adapt();
>>
>> std::vector<getfem::pglobal_function> vfunc(6);
>> for (unsigned i = 0; i < vfunc.size(); ++i){
>> getfem::abstract_xy_function *s =
>> new getfem::crack_singular_xy_function(i);
>> getfem::abstract_xy_function *c =
>> new getfem::cutoff_xy_function(0, .2,.01,.49);
>> s = new getfem::product_of_xy_functions(*s, *c);
>> vfunc[i] = getfem::global_function_on_level_set(ls, *s);
>> }
>>
>> getfem::mesh_fem_level_set mfls(mls, mf);
>>
>> getfem::mesh_fem_global_function mf_sing(mesh,3);
>>
>> mf_sing.set_functions(vfunc);
>>
>> getfem::mesh_fem_product mf_asympt(mfls, mf_sing);
>>
>> getfem::mesh_fem_product mfu(mf_asympt);
>>
>> getfem::mesh_im_level_set mim(mls,
>> getfem::mesh_im_level_set::INTEGRATE_ALL,
>> getfem::int_method_descriptor("IM_TETRAHEDRON(6)"),
>> getfem::int_method_descriptor("IM_QUASI_POLAR(IM_TETRAHEDRON(8), 2)"));
>>
>>
>>
>> getfem::model md;
>> md.add_fem_variable("u", mfu);
>>
>>
>> md.add_initialized_scalar_data("cmu", cmu);
>> md.add_initialized_scalar_data("clambdastar", clambdastar);
>>
>> getfem::add_isotropic_linearized_elasticity_brick
>> (md, mim, "u", "clambdastar", "cmu");
>>
>>
>> getfem::add_normal_Dirichlet_condition_with_multipliers(md,mim,"u", 1,
>> 109);
>>
>> getfem::add_source_term_brick(md,mim,"u","[0,1640,0]", 108);
>>
>> gmm::iteration iter(residual, 1, 50);
>> getfem::standard_solve(md, iter,
>> getfem::rselect_linear_solver(md,"superlu"));
>>
>> getfem::standard_solve(md, iter);
>>
>> plain_vector U(mfu.nb_dof()); gmm::copy(md.real_variable("u"), U);
>> plain_vector VM(mfvm.nb_dof());
>> getfem::compute_isotropic_linearized_Von_Mises_or_Tresca
>> (md, "u", "clamabdastar", "cmu", mfvm, VM, false);
>>
>>
>> getfem::vtk_export exp2("d_w_vm.vtk", false);
>> exp2.exporting(mfu);
>> exp2.write_point_data(mfu, U, "displacement");
>> exp2.write_point_data(mfvm, VM, "Von Mises stress");
>>
>>
>> }
>>
>
> Thank you for any help in advance,
>
> Andy
>
>
> _______________________________________________
> Getfem-users mailing
> [email protected]https://mail.gna.org/listinfo/getfem-users
>
>
>
> --
>
> Yves Renard ([email protected]) tel : (33) 04.72.43.87.08
> Pole de Mathematiques, INSA-Lyon fax : (33) 04.72.43.85.29
> 20, rue Albert Einstein
> 69621 Villeurbanne Cedex, FRANCE
> http://math.univ-lyon1.fr/~renard
>
> ---------
>
>
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