Add option to use full finite strain tensor for strain weakening #1644
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| // Calculate and/or constrain the strain invariant of the previous timestep | ||
| if ( use_finite_strain_tensor == true ) | ||
| { | ||
| // Calculate second invarinat of left stretching tensor "L" |
| for (unsigned int q = 0; q < Tensor<2,dim>::n_independent_components ; ++q) | ||
| strain[Tensor<2,dim>::unrolled_to_component_indices(q)] = composition[q]; | ||
| const SymmetricTensor<2,dim> L = symmetrize( strain * transpose(strain) ); | ||
| strain_ii = std::fabs(second_invariant(L)); |
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cut off between strain weakening interval as well here?
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| // We need the velocity gradient for the finite strain (they are not included in material model inputs), | ||
| // so we get them from the finite element. | ||
| if (in.cell && use_finite_strain_tensor == true && this->get_timestep_number() > 0) |
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also test use_strain_weakening is true (or do an assert somewhere that use_finite_strain_tensor can only be true if use_strain_weakening is true)
| "$L = F * [F]^T$. In either case, the user specifies a single compositional " | ||
| "field for the finite strain invariant or multiple fields (4 in 2D, 9 in 3D) " | ||
| "for the finite strain tensor. These field(s) must be the first lised " | ||
| "compositional fields in the paramter file. Note that one or more of the finite strain " |
| "strain rate tensor and $dt$ is the time step size. In the case of the " | ||
| "full strain tensor $F$, the finite strain magnitude is derived from the " | ||
| "second invariant of the symmetric stretching tensor $L$, where " | ||
| "$L = F * [F]^T$. In either case, the user specifies a single compositional " |
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"In either case" sounds confusing to me, because you don't do the same thing in either case. Either you specify a single field or multiple fields
| set Names of fields = s11, s12, s21, s22 | ||
| end | ||
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| # All compositional fields have an initial value of 0 |
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This is not true, the first and fourth field have a value of 0.5
| if (use_strain_weakening && this->get_timestep_number() > 0) | ||
| double edot_ii = 0.; | ||
| double e_ii = 0.; | ||
| if (use_strain_weakening == true && use_finite_strain_tensor == false && this->get_timestep_number() > 0) |
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Why should the timestep be bigger than 0?
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This is to test if we are not on the first time step.
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please run astyle! /run-tests |
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Thanks for the review Anne! All of your comments should now be addressed. |
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| fe_values.reinit (*in.cell); | ||
| fe_values[this->introspection().extractors.velocities].get_function_gradients (this->get_solution(), | ||
| velocity_gradients); |
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The gcc-hd compiler build error seems to be related to retrieving the fe_values here. Any suggestions for a fix I can apply?
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Sorry, should have quoted lines 394-397, but the build error there propagates down to these lines as well.
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I think you need #include <deal.II/fe/fe_values.h> at the top of the file.
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Doh, of course. Thank you.
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Unless there are further requested changes, this should be ready to merge. |
| "The finite strain invariant or full strain tensor is calculated through " | ||
| "compositional fields within the material model. This implementation is " | ||
| "identical to the compositional field finite strain plugin and cookbook " | ||
| "described in the manual (author: Gassmoeller). If the user selects to track " |
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Please add Juliane, we contributed the section together.
| @@ -0,0 +1,116 @@ | |||
| # Global parameters | |||
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I think you forgot the output for this test.
Provide an option to use the full finite strain tensor for the strain weakening component of the visco_plastic material model. There is a warning in the material model's documentation about the pitfalls of this option.
@anne-glerum - Any and all feedback welcome!