[MPM] example not working

[jginternational]

As pointed in #551 We need to update modelpart names & paths

[jginternational]

Traceback (most recent call last):
  File "C:\Users\garat\AppData\Local\Temp\mpm_2d_fallingsandball_calculategid.gid\MainKratos.py", line 39, in <module>
    simulation.Run()
  File "E:\Deploy_Kratos\KratosMultiphysics\analysis_stage.py", line 47, in Run
    self.Initialize()
  File "C:\Users\garat\AppData\Local\Temp\mpm_2d_fallingsandball_calculategid.gid\MainKratos.py", line 20, in Initialize
    super().Initialize()
  File "E:\Deploy_Kratos\KratosMultiphysics\analysis_stage.py", line 82, in Initialize
    self._GetSolver().PrepareModelPart()
  File "E:\Deploy_Kratos\KratosMultiphysics\ParticleMechanicsApplication\mpm_solver.py", line 114, in PrepareModelPart
    self.__ExecuteCheckAndPrepare()
  File "E:\Deploy_Kratos\KratosMultiphysics\ParticleMechanicsApplication\mpm_solver.py", line 458, in __ExecuteCheckAndPrepare
    materials_imported = self.__ImportConstitutiveLaws()
  File "E:\Deploy_Kratos\KratosMultiphysics\ParticleMechanicsApplication\mpm_solver.py", line 473, in __ImportConstitutiveLaws
    KratosMultiphysics.ReadMaterialsUtility(material_settings, self.model)
RuntimeError: Error: The ModelPart named : "Parts_Grid_Grid" was not found as SubModelPart of : "Initial_MPM_Material". The total input string was "Initial_MPM_Material.Parts_Grid_Grid"

in kratos/containers/model.cpp:149:Model::GetModelPart
   kratos/containers/model.cpp:165:Model::GetModelPart
   kratos/utilities/read_materials_utility.cpp:147:ReadMaterialsUtility::GetPropertyBlock
   kratos/utilities/read_materials_utility.cpp:82:ReadMaterialsUtility::ReadMaterialsUtility

[VeronikaSinger]

Hi @jginternational

there is a problem in the ParticleMaterials.json. The constitutive variables should be written only for the Initial_MPM_Material (Body Mesh) and not for both - the blue marked text should be deleted:

[jginternational]

Hi @VeronikaSinger

I fixed that, but now I'm experiencing this issue:

::[Particle Mechanics Analysis]:: : STEP:  146 
::[Particle Mechanics Analysis]:: : TIME:  0.7300000000000005 
::[Particle GiD Output Process]:: : [Spent time for output =  0.05539870262145996 sec] 
::[Particle Mechanics Analysis]:: : STEP:  147 
::[Particle Mechanics Analysis]:: : TIME:  0.7350000000000005 
::[Particle Mechanics Analysis]:: : STEP:  148 
::[Particle Mechanics Analysis]:: : TIME:  0.7400000000000005 
UpdatedLagrangian:  Element: 4899
UpdatedLagrangian:  Element position: [3](1.48692,0.0544129,0)
UpdatedLagrangian:  Element velocity: [3](-11.0101,-5.60785,0)
UpdatedLagrangian:  Shape functions: [1,3]((0.0720337,0.128113,0.799853))
UpdatedLagrangian:  Quadrature points: 1
UpdatedLagrangian:  Parent geometry ID: 4611686018461428544
UpdatedLagrangian:  Parent geometry number of points: 3
UpdatedLagrangian:  NODE [751]: (Current position: [3](1.40909,0.0788095,0)) 
UpdatedLagrangian:  ---Current Disp: [3](-0.00915925,-0.0549346,0) (Previour Disp: [3](0,0,0))
UpdatedLagrangian:  NODE [728]: (Current position: [3](1.45455,0,0)) 
UpdatedLagrangian:  ---Current Disp: [3](0,0,0) (Previour Disp: [3](0,0,0))
UpdatedLagrangian:  NODE [703]: (Current position: [3](1.49912,0.0609311,0)) 
UpdatedLagrangian:  ---Current Disp: [3](-0.00505197,-0.0283005,0) (Previour Disp: [3](-0.0509013,-0.0251841,0))
UpdatedLagrangian:  ---Contact_Force: NULL 
UpdatedLagrangian:  ---Contact_Force: NULL 
UpdatedLagrangian:  ---Contact_Force: NULL 
terminate called after throwing an instance of 'Kratos::Exception'
  what():  Error: MPM UPDATED LAGRANGIAN DISPLACEMENT ELEMENT INVERTED: |F|<0  detF = -0.291496

in kratos/Kratos/applications/ParticleMechanicsApplication/custom_elements/updated_lagrangian.cpp:245:virtual void UpdatedLagrangian::SetGeneralVariables(UpdatedLagrangian::GeneralVariables&, ConstitutiveLaw::Parameters&, const Vector&)
   kratos/Kratos/applications/ParticleMechanicsApplication/custom_elements/updated_lagrangian.cpp:336:virtual void UpdatedLagrangian::CalculateElementalSystem(Element::MatrixType&, Element::VectorType&, const ProcessInfo&, bool, bool)
   kratos/Kratos/applications/ParticleMechanicsApplication/custom_strategies/schemes/mpm_residual_based_bossak_scheme.hpp:448:void MPMResidualBasedBossakScheme<TSparseSpace, TDenseSpace>::CalculateRHSContribution(Element&, MPMResidualBasedBossakScheme<TSparseSpace, TDenseSpace>::LocalSystemVectorType&, Element::EquationIdVectorType&, const ProcessInfo&) [with TSparseSpace = UblasSpace<double, boost::numeric::ublas::compressed_matrix<...>, boost::numeric::ublas::vector<double> >; TDenseSpace = UblasSpace<double, boost::numeric::ublas::matrix<double>, boost::numeric::ublas::vector<double> >; MPMResidualBasedBossakScheme<TSparseSpace, TDenseSpace>::LocalSystemVectorType = boost::numeric::ublas::vector<double>; Element::EquationIdVectorType = vector<long unsigned int>]

Aborted (core dumped)

[VeronikaSinger]

Hi this problem occurs if the defomation is too large within one time step and hardly depends on the discretization. How did you chooose the mesh size for this example? If I generate the mesh as proposed by GiD I don't receive this error. However, if triangles are used, the number of material points (PARTICLES_PER_ELEMENT) should be changed to 3 or 6 instead of 10 to avoid the warnings.