Re: [deal.II] output derived quanteties (gradients of vector valued solution like strain)
On 3/10/23 13:05, Konrad Schneider wrote: ** Thanks. That was too easy. How should one know this... Actually in the documentation (https://www.dealii.org/current/doxygen/deal.II/classDataPostprocessorTensor.html) the command data_out.write_vtk (output); appears in the example. Maybe it should be changed to data_out.write_vtu (output); Furthermore, may I suggest, that it might be of some value to add the data output of stresses to one of the elasticity tutorials (maybe add it to step-8), since evaluating stresses (especially von mises stresses) is one of the major tasks in "pure" solid mechanics plus there is this pitfall that we have to use the vtu-format for tensor data. Konrad, yes, this had been pointed out a couple of months ago, and the current developer documentation already points that out as well: https://www.dealii.org/developer/doxygen/deal.II/classDataPostprocessorTensor.html I've taken the liberty to also write a patch that makes the error message clearer: https://github.com/dealii/dealii/pull/14875 Best W. -- Wolfgang Bangerth email: bange...@colostate.edu www: http://www.math.colostate.edu/~bangerth/ -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/0c523295-9d15-7c82-1f67-355e25f66840%40colostate.edu.
Re: [deal.II] output derived quanteties (gradients of vector valued solution like strain)
Thanks. That was too easy. How should one know this... Actually in the documentation (https://www.dealii.org/current/doxygen/deal.II/classDataPostprocessorTensor.html) the command data_out.write_vtk (output); appears in the example. Maybe it should be changed to data_out.write_vtu (output); Furthermore, may I suggest, that it might be of some value to add the data output of stresses to one of the elasticity tutorials (maybe add it to step-8), since evaluating stresses (especially von mises stresses) is one of the major tasks in "pure" solid mechanics plus there is this pitfall that we have to use the vtu-format for tensor data. But thanks anyway for the quick response (again). Best regards Konrad Wolfgang Bangerth schrieb am Freitag, 10. März 2023 um 20:35:09 UTC+1: > On 3/10/23 07:41, Konrad Schneider wrote: > > > > I am using deal.ii version 9.4 and am wondering what I did wrong here. > Do you > > have any suggestions? > > The VTK writer simply doesn't support writing tensor data. Use the VTU > writer > instead. > > Best > W. > > -- > > Wolfgang Bangerth email: bang...@colostate.edu > www: http://www.math.colostate.edu/~bangerth/ > > > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/c5d4f3f2-e741-4008-a712-e7d108fb7064n%40googlegroups.com.
Re: [deal.II] output derived quanteties (gradients of vector valued solution like strain)
On 3/10/23 07:41, Konrad Schneider wrote: I am using deal.ii version 9.4 and am wondering what I did wrong here. Do you have any suggestions? The VTK writer simply doesn't support writing tensor data. Use the VTU writer instead. Best W. -- Wolfgang Bangerth email: bange...@colostate.edu www: http://www.math.colostate.edu/~bangerth/ -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/238bfb06-e8e6-88ce-295f-fa9f4f5ed78b%40colostate.edu.
[deal.II] output derived quanteties (gradients of vector valued solution like strain)
Dear Forum,
I tried to follow the instructions of the DataPostprocessorTensor class to
output the gradient of a vector valued solution. Therefore I tried to adopt
step-8. However, I am getting the following error message:
An error occurred in line <5640> of file
in function
void dealii::DataOutBase::write_vtk(const
std::vector >&, const
std::vector >&, const
std::vector,
std::allocator >,
dealii::DataComponentInterpretation::DataComponentInterpretation> >&, const
dealii::DataOutBase::VtkFlags&, std::ostream&) [with int dim = 2; int
spacedim = 2; std::ostream = std::basic_ostream]
The violated condition was:
std::get<3>(nonscalar_data_range) !=
DataComponentInterpretation::component_is_part_of_tensor
Additional information:
You are trying to use functionality in deal.II that is currently not
implemented. In many cases, this indicates that there simply didn't
appear much of a need for it, or that the author of the original code
did not have the time to implement a particular case. If you hit this
exception, it is therefore worth the time to look into the code to
find out whether you may be able to implement the missing
functionality. If you do, please consider providing a patch to the
deal.II development sources (see the deal.II website on how to
contribute).
I am using deal.ii version 9.4 and am wondering what I did wrong here. Do
you have any suggestions?
Best regards
Konrad
--
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#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
namespace Step8
{
using namespace dealii;
template
class ElasticProblem{
public:
ElasticProblem();
void run();
private:
void setup_system();
void assemble_system();
void solve();
void refine_grid();
void output_results() const;
Triangulation triangulation;
DoFHandlerdof_handler;
FESystem fe;
AffineConstraints constraints;
SparsityPattern sparsity_pattern;
SparseMatrix system_matrix;
Vector solution;
Vector system_rhs;
};
template
void right_hand_side(const std::vector> &points,std::vector> & values){
AssertDimension(values.size(), points.size());
Assert(dim >= 2, ExcNotImplemented());
Point point_1, point_2;
point_1(0) = 0.5;
point_2(0) = -0.5;
for (unsigned int point_n = 0; point_n < points.size(); ++point_n)
{
if (((points[point_n] - point_1).norm_square() < 0.2 * 0.2) ||
((points[point_n] - point_2).norm_square() < 0.2 * 0.2))
values[point_n][0] = 1.0;
else
values[point_n][0] = 0.0;
if (points[point_n].norm_square() < 0.2 * 0.2)
values[point_n][1] = 1.0;
else
values[point_n][1] = 0.0;
}
}
template
ElasticProblem::ElasticProblem()
: dof_handler(triangulation)
, fe(FE_Q(1), dim)
{}
template
void ElasticProblem::setup_system()
{
dof_handler.distribute_dofs(fe);
solution.reinit(dof_handler.n_dofs());
system_rhs.reinit(dof_handler.n_dofs());
constraints.clear();
DoFTools::make_hanging_node_constraints(dof_handler, constraints);
VectorTools::interpolate_boundary_values(dof_handler,
0,
Functions::ZeroFunction(dim),
constraints);
constraints.close();
DynamicSparsityPattern dsp(dof_handler.n_dofs(), dof_handler.n_dofs());
DoFTools::make_sparsity_pattern(dof_handler,
dsp,
constraints,
/*keep_constrained_dofs = */ false);
sparsity_pattern.copy_from(dsp);
system_matrix.reinit(sparsity_pattern);
}
template
void ElasticProblem::assemble_system()
{
QGauss quadrature_formula(fe.degree + 1);
FEValues fe_values(fe,
quadrature_formula,
update_values | update_gradients |
update_quadrature_points | update_JxW_values);
const unsigned int dofs_per_cell = fe.n_dofs_per_cell();
const unsigned int n_q_points= quadrature_formula.size();
FullMatrix cell_matrix(dofs_per_cell, dofs_per_cell);
Vector cell_rhs(dofs_per_cell);
std::vector local_dof_indices(dofs_per_cell);
std::vector lambda_values(n_q_points)
