Add temperature parameters for RefJC viscoplasticity, along with GP output by dragos-ana · Pull Request #1879 · 4C-multiphysics/4C

dragos-ana · 2026-03-20T14:24:29Z

Extended Reformulated Johnson-Cook with temperature parameters and pre-evaluate context handling
Added runtime Gauss Point output registration/evaluation for multiplicative split material, elasto-viscoplastic material and viscoplastic laws
Saved additional inelastic state data (stress and defgrad)
Updated unit tests and affected input files for new required Reformulated Johnson-Cook parameters

Copilot

Pull request overview

Extends the Reformulated Johnson–Cook viscoplasticity model with temperature-related parameters and introduces runtime Gauss-point output plumbing for multiplicative-split inelastic materials and viscoplastic laws.

Changes:

Added temperature parameters (reference temperature, melting temperature, temperature sensitivity) to Reformulated Johnson–Cook and updated affected tests/input files.
Extended viscoplastic law interface to accept a parameter list in pre_evaluate() and added hooks for GP runtime output registration/evaluation.
Added runtime output forwarding in multiplicative split material and inelastic defgrad factors; added additional state packing (e.g., defgrad / equiv stress history).

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
unittests/mat/vplast/4C_vplast_reform_johnsoncook_test.cpp	Updates unit test to provide temperature parameters and call new `pre_evaluate(params,gp)` signature.
unittests/mat/4C_inelastic_defgrad_factors_test.cpp	Updates test material input container to include new required RefJC temperature parameters.
tests/input_files/poro_solid_nitsche_contact3D_twoelem_twosided_new_struc_vplast.4C.yaml	Adds required RefJC temperature parameters to test input.
tests/input_files/poro_new_solid_nitsche_contact3D_twoelem_new_struc_vplast.4C.yaml	Adds required RefJC temperature parameters to test input.
tests/input_files/poro_new_solid_nitsche_contact3D_new_struc_vplast.4C.yaml	Adds required RefJC temperature parameters to test input.
tests/input_files/mat_transviso_viscoplast_refJC_standard_substep.4C.yaml	Adds required RefJC temperature parameters to test input.
tests/input_files/mat_transviso_viscoplast_refJC_log_substep.4C.yaml	Adds required RefJC temperature parameters to test input.
tests/input_files/mat_iso_viscoplast_refJC_log_substep.4C.yaml	Adds required RefJC temperature parameters to test input.
src/mat/vplast/4C_mat_vplast_reform_johnsoncook.hpp	Adds temperature parameter accessors and new GP output/state members; updates law interface overrides.
src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp	Implements temperature handling in `pre_evaluate()`, GP output for yield strength, and packing/unpacking of law state.
src/mat/vplast/4C_mat_vplast_law.hpp	Updates `pre_evaluate` signature to accept `Teuchos::ParameterList`; adds runtime output hooks to the law interface.
src/mat/4C_mat_multiplicative_split_defgrad_elasthyper.hpp	Adds runtime output forwarding API declarations to multiplicative split material and its handler.
src/mat/4C_mat_multiplicative_split_defgrad_elasthyper.cpp	Implements runtime output forwarding to inelastic defgrad factors.
src/mat/4C_mat_inelastic_defgrad_factors_service.hpp	Extends error enum and time-step quantities to store additional history (equiv stress, defgrad).
src/mat/4C_mat_inelastic_defgrad_factors_service.cpp	Initializes/resizes/updates/packs/unpacks new time-step quantities fields.
src/mat/4C_mat_inelastic_defgrad_factors.hpp	Adds runtime output hooks to inelastic defgrad factors interface and overrides in the viscoplastic factor.
src/mat/4C_mat_inelastic_defgrad_factors.cpp	Passes parameter list down to viscoplastic law `pre_evaluate`, improves matrix-log error handling, and adds GP runtime output evaluation.
src/global_legacy_module/4C_global_legacy_module_validmaterials.cpp	Registers new required RefJC input parameters in material validation/spec.

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.hpp

src/mat/4C_mat_inelastic_defgrad_factors.cpp

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.hpp

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp

src/global_legacy_module/4C_global_legacy_module_validmaterials.cpp

src/mat/vplast/4C_mat_vplast_law.hpp

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp

rjoussen · 2026-03-22T10:19:36Z

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp

+  InelasticDefgradTransvIsotropElastViscoplastUtils::ErrorType yield_strength_err_status{
+      InelasticDefgradTransvIsotropElastViscoplastUtils::ErrorType::no_errors};
  const double yield_strength =
-      (parameter()->init_yield_strength() +
-          parameter()->isotrop_harden_prefac() *
-              std::pow(equiv_plastic_strain, parameter()->isotrop_harden_exp()));
+      compute_flow_resistance(equiv_stress, equiv_plastic_strain, yield_strength_err_status);
+  FOUR_C_ASSERT_ALWAYS(yield_strength_err_status ==
+                           InelasticDefgradTransvIsotropElastViscoplastUtils::ErrorType::no_errors,
+      "Something went wrong when evaluating the yield stress: error = {}",
+      EnumTools::enum_name(yield_strength_err_status));


It seems like the error_status parameter is unused in compute_flow_resistance but adds a lot of code. I would remove it.

True for now ;) This gets used for the Anand law that I will add in a couple of weeks, but I already introduced the common framework here.

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.hpp

rjoussen · 2026-03-22T10:41:47Z

src/mat/4C_mat_inelastic_defgrad_factors.cpp


    Core::LinAlg::Matrix<10, 10> jacMat(Core::LinAlg::Initialization::zero);
-    viscoplastic_law_->pre_evaluate(gp_);  // set last_substep <- last_
+    viscoplastic_law_->pre_evaluate(params_, gp_);  // set last_substep <- last_


Is this pre_evaluate needed here?

Good question. The original motivation was to set correct history variables in the case of substepping for the subsequent evaluations. Since my approach has deviated a lot from the original substepping approach, I do not actively use this anymore. But I think that an additional pre_evaluate call does not break anything, although I will have to look at this in more detail at some point. Thanks for spotting it!

rjoussen · 2026-03-22T10:45:51Z

src/mat/4C_mat_inelastic_defgrad_factors_service.hpp

      std::vector<double> last_plastic_strain;

+      //! equivalent stress at the previous time instant (for all Gauss points)
+      std::vector<double> last_equiv_stress;


I don't think storing last_equiv_stress is necessary. As far as I can see, it is only used for plotting anyway, so it could be sufficient to only store current. This might also apply to all other TimeStepQuantities which are not "real" history variables.

Again, not necessary now, but necessary in future PRs.
Sadly, it's kind of difficult to add only code that is directly used, and I had to add such "unnecessary code" to pave the way for upcoming changes.
But thanks anyway for spotting this.

src/mat/vplast/4C_mat_vplast_law.hpp

- Extended Reformulated Johnson-Cook with temperature parameters and pre-evaluate context handling. Also improved handling of perfect plasticity. - Added runtime gauss-point output registration/evaluation for multiplicative split material, elasto-viscoplastic material and viscoplastic laws - Saved additional inelastic state data (stress and defgrad) - Updated unit tests and affected input files for new required Reformulated Johnson-Cook parameters Temp: Add copilot changes

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp

dragos-ana self-assigned this Mar 20, 2026

dragos-ana requested a review from Copilot March 20, 2026 14:25

Copilot started reviewing on behalf of dragos-ana March 20, 2026 14:25 View session

dragos-ana changed the title ~~Add further parameters for RefJC viscoplasticity, along with GP output~~ Add temperature parameters for RefJC viscoplasticity, along with GP output Mar 20, 2026

Copilot AI reviewed Mar 20, 2026

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dragos-ana force-pushed the viscoplast-modify-viscoplast-laws-add-return-mapping branch 2 times, most recently from 3557745 to 8e3279c Compare March 20, 2026 18:52

dragos-ana requested review from c-p-schmidt and rjoussen March 20, 2026 18:55

rjoussen reviewed Mar 22, 2026

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c-p-schmidt reviewed Mar 23, 2026

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src/mat/vplast/4C_mat_vplast_law.hpp Show resolved Hide resolved

dragos-ana force-pushed the viscoplast-modify-viscoplast-laws-add-return-mapping branch from 8e3279c to 4185208 Compare March 27, 2026 19:12

c-p-schmidt approved these changes Mar 30, 2026

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src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp Show resolved Hide resolved

src/mat/vplast/4C_mat_vplast_reform_johnsoncook.cpp Show resolved Hide resolved

dragos-ana requested a review from rjoussen March 30, 2026 09:12

dragos-ana enabled auto-merge March 30, 2026 09:13

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dragos-ana commented Mar 20, 2026 •

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