Verification tests and demos

src/neml2/models/solid_mechanics/FredrickArmstrongPlasticHardening.cxx

@@ -47,6 +47,9 @@ FredrickArmstrongPlasticHardening::expected_options()
   options.set_input("back_stress") = VariableName("state", "internal", "X");
   options.set("back_stress").doc() = "Back stress";
 
+  options.set_output("back_stress_rate");
+  options.set("back_stress_rate").doc() = "Back stress rate, defaults to back_stress + _rate";
+
   options.set_input("flow_direction") = VariableName("state", "internal", "NM");
   options.set("flow_direction").doc() = "Flow direction";
 
@@ -63,7 +66,9 @@ FredrickArmstrongPlasticHardening::FredrickArmstrongPlasticHardening(const Optio
   : FlowRule(options),
     _X(declare_input_variable<SR2>("back_stress")),
     _NM(declare_input_variable<SR2>("flow_direction")),
-    _X_dot(declare_output_variable<SR2>(_X.name().with_suffix("_rate"))),
+    _X_dot(declare_output_variable<SR2>(options.get<VariableName>("back_stress_rate").empty()
+                                            ? _X.name().with_suffix("_rate")
+                                            : options.get<VariableName>("back_stress_rate"))),
     _C(declare_parameter<Scalar>("C", "C", true)),
     _g(declare_parameter<Scalar>("g", "g", true))
 {

tests/regression/solid_mechanics/recovery/nonassociative_isotropic_kinematic/model.i

@@ -0,0 +1,166 @@
+[Tensors]
+  [end_time]
+    type = LogspaceScalar
+    start = -1
+    end = 5
+    nstep = 20
+  []
+  [times]
+    type = LinspaceScalar
+    start = 0
+    end = end_time
+    nstep = 100
+  []
+  [exx]
+    type = FullScalar
+    batch_shape = '(20)'
+    value = 0.1
+  []
+  [eyy]
+    type = FullScalar
+    batch_shape = '(20)'
+    value = -0.05
+  []
+  [ezz]
+    type = FullScalar
+    batch_shape = '(20)'
+    value = -0.05
+  []
+  [max_strain]
+    type = FillSR2
+    values = 'exx eyy ezz'
+  []
+  [strains]
+    type = LinspaceSR2
+    start = 0
+    end = max_strain
+    nstep = 100
+  []
+[]
+
+[Drivers]
+  [driver]
+    type = SolidMechanicsDriver
+    model = 'model'
+    times = 'times'
+    prescribed_strains = 'strains'
+    save_as = 'result.pt'
+  []
+  [regression]
+    type = TransientRegression
+    driver = 'driver'
+    reference = 'gold/result.pt'
+  []
+[]
+
+[Solvers]
+  [newton]
+    type = Newton
+  []
+[]
+
+[Models]
+  [isoharden]
+    type = SlopeSaturationVoceIsotropicHardening
+    saturated_hardening = 100
+    initial_hardening_rate = 1200.0
+  []
+  [kinharden]
+    type = SR2LinearCombination
+    from_var = 'state/internal/X1 state/internal/X2'
+    to_var = 'state/internal/X'
+  []
+  [mandel_stress]
+    type = IsotropicMandelStress
+  []
+  [overstress]
+    type = SR2LinearCombination
+    to_var = 'state/internal/O'
+    from_var = 'state/internal/M state/internal/X'
+    coefficients = '1 -1'
+  []
+  [vonmises]
+    type = SR2Invariant
+    invariant_type = 'VONMISES'
+    tensor = 'state/internal/O'
+    invariant = 'state/internal/s'
+  []
+  [yield]
+    type = YieldFunction
+    yield_stress = 5
+    isotropic_hardening = 'state/internal/k'
+  []
+  [flow]
+    type = ComposedModel
+    models = 'overstress vonmises yield'
+  []
+  [normality]
+    type = Normality
+    model = 'flow'
+    function = 'state/internal/fp'
+    from = 'state/internal/M'
+    to = 'state/internal/NM'
+  []
+  [flow_rate]
+    type = PerzynaPlasticFlowRate
+    reference_stress = 100
+    exponent = 2
+  []
+  [X1rate]
+    type = FredrickArmstrongPlasticHardening
+    back_stress = 'state/internal/X1'
+    C = 10000
+    g = 100
+  []
+  [X2rate]
+    type = FredrickArmstrongPlasticHardening
+    back_stress = 'state/internal/X2'
+    C = 1000
+    g = 9
+  []
+  [Eprate]
+    type = AssociativePlasticFlow
+  []
+  [Erate]
+    type = SR2VariableRate
+    variable = 'forces/E'
+    rate = 'forces/E_rate'
+  []
+  [Eerate]
+    type = SR2LinearCombination
+    from_var = 'forces/E_rate state/internal/Ep_rate'
+    to_var = 'state/internal/Ee_rate'
+    coefficients = '1 -1'
+  []
+  [elasticity]
+    type = LinearIsotropicElasticity
+    youngs_modulus = 1e5
+    poisson_ratio = 0.3
+    rate_form = true
+  []
+  [integrate_k]
+    type = ScalarBackwardEulerTimeIntegration
+    variable = 'state/internal/k'
+  []
+  [integrate_X1]
+    type = SR2BackwardEulerTimeIntegration
+    variable = 'state/internal/X1'
+  []
+  [integrate_X2]
+    type = SR2BackwardEulerTimeIntegration
+    variable = 'state/internal/X2'
+  []
+  [integrate_stress]
+    type = SR2BackwardEulerTimeIntegration
+    variable = 'state/S'
+  []
+  [implicit_rate]
+    type = ComposedModel
+    models = 'isoharden kinharden mandel_stress overstress vonmises yield normality flow_rate Eprate X1rate X2rate Erate Eerate elasticity integrate_stress integrate_k integrate_X1 integrate_X2'
+  []
+  [model]
+    type = ImplicitUpdate
+    implicit_model = 'implicit_rate'
+    solver = 'newton'
+  []
+[]

tests/regression/solid_mechanics/recovery/static_recovery/model.i

@@ -0,0 +1,204 @@
+[Tensors]
+  [end_time]
+    type = LogspaceScalar
+    start = -1
+    end = 5
+    nstep = 20
+  []
+  [times]
+    type = LinspaceScalar
+    start = 0
+    end = end_time
+    nstep = 100
+  []
+  [exx]
+    type = FullScalar
+    batch_shape = '(20)'
+    value = 0.1
+  []
+  [eyy]
+    type = FullScalar
+    batch_shape = '(20)'
+    value = -0.05
+  []
+  [ezz]
+    type = FullScalar
+    batch_shape = '(20)'
+    value = -0.05
+  []
+  [max_strain]
+    type = FillSR2
+    values = 'exx eyy ezz'
+  []
+  [strains]
+    type = LinspaceSR2
+    start = 0
+    end = max_strain
+    nstep = 100
+  []
+[]
+
+[Drivers]
+  [driver]
+    type = SolidMechanicsDriver
+    model = 'model'
+    times = 'times'
+    prescribed_strains = 'strains'
+    save_as = 'result.pt'
+  []
+  [regression]
+    type = TransientRegression
+    driver = 'driver'
+    reference = 'gold/result.pt'
+  []
+[]
+
+[Solvers]
+  [newton]
+    type = Newton
+  []
+[]
+
+[Models]
+  [isoharden]
+    type = SlopeSaturationVoceIsotropicHardening
+    saturated_hardening = 100
+    initial_hardening_rate = 1200.0
+    isotropic_hardening_rate = 'state/internal/k_rate_base'
+  []
+  [isoharden_recovery]
+    type = IsotropicHardeningStaticRecovery
+    n = 2.0
+    tau = 1000.0
+  []
+  [isoharden_total]
+    type = ScalarLinearCombination
+    to_var = 'state/internal/k_rate'
+    from_var = 'state/internal/k_rate_base state/internal/k_recovery_rate'
+    coefficients = '1 1'
+  []
+  [kinharden]
+    type = SR2LinearCombination
+    from_var = 'state/internal/X1 state/internal/X2'
+    to_var = 'state/internal/X'
+  []
+  [mandel_stress]
+    type = IsotropicMandelStress
+  []
+  [overstress]
+    type = SR2LinearCombination
+    to_var = 'state/internal/O'
+    from_var = 'state/internal/M state/internal/X'
+    coefficients = '1 -1'
+  []
+  [vonmises]
+    type = SR2Invariant
+    invariant_type = 'VONMISES'
+    tensor = 'state/internal/O'
+    invariant = 'state/internal/s'
+  []
+  [yield]
+    type = YieldFunction
+    yield_stress = 5
+    isotropic_hardening = 'state/internal/k'
+  []
+  [flow]
+    type = ComposedModel
+    models = 'overstress vonmises yield'
+  []
+  [normality]
+    type = Normality
+    model = 'flow'
+    function = 'state/internal/fp'
+    from = 'state/internal/M'
+    to = 'state/internal/NM'
+  []
+  [flow_rate]
+    type = PerzynaPlasticFlowRate
+    reference_stress = 100
+    exponent = 2
+  []
+  [X1rate]
+    type = FredrickArmstrongPlasticHardening
+    back_stress = 'state/internal/X1'
+    back_stress_rate = 'state/internal/X1_rate_base'
+    C = 10000
+    g = 100
+  []
+  [X1_recovery]
+    type = KinematicHardeningStaticRecovery
+    back_stress = 'state/internal/X1'
+    n = 2.0
+    tau = 1000.0
+  []
+  [X1_total]
+    type = SR2LinearCombination
+    to_var = 'state/internal/X1_rate'
+    from_var = 'state/internal/X1_rate_base state/internal/X1_recovery_rate'
+    coefficients = '1 1'
+  []
+  [X2rate]
+    type = FredrickArmstrongPlasticHardening
+    back_stress = 'state/internal/X2'
+    back_stress_rate = 'state/internal/X2_rate_base'
+    C = 1000
+    g = 9
+  []
+  [X2_recovery]
+    type = KinematicHardeningStaticRecovery
+    back_stress = 'state/internal/X2'
+    n = 2.5
+    tau = 500.0
+  []
+  [X2_total]
+    type = SR2LinearCombination
+    to_var = 'state/internal/X2_rate'
+    from_var = 'state/internal/X2_rate_base state/internal/X2_recovery_rate'
+    coefficients = '1 1'
+  []
+  [Eprate]
+    type = AssociativePlasticFlow
+  []
+  [Erate]
+    type = SR2VariableRate
+    variable = 'forces/E'
+    rate = 'forces/E_rate'
+  []
+  [Eerate]
+    type = SR2LinearCombination
+    from_var = 'forces/E_rate state/internal/Ep_rate'
+    to_var = 'state/internal/Ee_rate'
+    coefficients = '1 -1'
+  []
+  [elasticity]
+    type = LinearIsotropicElasticity
+    youngs_modulus = 1e5
+    poisson_ratio = 0.3
+    rate_form = true
+  []
+  [integrate_k]
+    type = ScalarBackwardEulerTimeIntegration
+    variable = 'state/internal/k'
+  []
+  [integrate_X1]
+    type = SR2BackwardEulerTimeIntegration
+    variable = 'state/internal/X1'
+  []
+  [integrate_X2]
+    type = SR2BackwardEulerTimeIntegration
+    variable = 'state/internal/X2'
+  []
+  [integrate_stress]
+    type = SR2BackwardEulerTimeIntegration
+    variable = 'state/S'
+  []
+  [implicit_rate]
+    type = ComposedModel
+    models = 'isoharden isoharden_recovery isoharden_total kinharden mandel_stress overstress vonmises yield normality flow_rate Eprate X1rate X1_recovery X1_total X2rate X2_recovery X2_total Erate Eerate elasticity integrate_stress integrate_k integrate_X1 integrate_X2'
+  []
+  [model]
+    type = ImplicitUpdate
+    implicit_model = 'implicit_rate'
+    solver = 'newton'
+  []
+[]