Viscoplastic general flow rule¶

Overview¶

This class specializes the General flow rule interface to match the standard definition of a generic viscoplastic flow rule. It defines the stress and hardening rates as

$\dot{\bm{\sigma}} = \mathbf{\mathfrak{C}}:\left(\dot{\bm{\varepsilon}}-\mathbf{g}_{\gamma}\dot{\gamma}-\mathbf{g}_{T}\dot{T}-\mathbf{g}_{t}\right) \dot{\bm{\alpha}} = \mathbf{h}_{\gamma}\dot{\gamma}+\mathbf{h}_{T}\dot{T}+\mathbf{h}_{t}.$

A Elasticity models interface defines the stiffness tensor and a viscoplastic flow rule interface defines the scalar flow rate $\dot{\gamma}$ , the flow functions $\mathbf{g}_\gamma$ , $\mathbf{g}_T$ , and $\mathbf{g}_t$ and the hardening functions $\mathbf{h}_\gamma$ , $\mathbf{h}_T$ , and $\mathbf{h}_t$ .

Parameters¶

Parameter	Object type	Description	Default
`elastic`	`neml::LinearElasticModel`	Elasticity model	No
`flow`	`neml::ViscoPlasticFlowRule`	Viscoplastic flow rule interface	No

Class description¶

class TVPFlowRule : public neml::GeneralFlowRule ¶

Thermo-visco-plasticity.

Public Functions

TVPFlowRule(ParameterSet &params)¶: Parameters: elastic model and a viscoplastic flow rule.

virtual void populate_hist(History &h) const¶: Setup the internal state.

virtual void init_hist(History &h) const¶: Initialize history.

virtual void s(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const sdot)¶: Stress rate.

virtual void ds_ds(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const d_sdot)¶: Partial of stress rate wrt stress.

virtual void ds_da(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const d_sdot)¶: Partial of stress rate wrt history.

virtual void ds_de(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const d_sdot)¶: Partial of stress rate wrt strain rate.

virtual void a(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const adot)¶: History rate.

virtual void da_ds(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const d_adot)¶: Partial of history rate wrt stress.

virtual void da_da(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const d_adot)¶: Partial of history rate wrt history.

virtual void da_de(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double *const d_adot)¶: Partial of history rate wrt strain rate.

virtual void work_rate(const double *const s, const double *const alpha, const double *const edot, double T, double Tdot, double &p_rate)¶: The implementation needs to define inelastic dissipation.

virtual void elastic_strains(const double *const s_np1, double T_np1, double *const e_np1) const¶: The implementation needs to define elastic strain.

virtual void set_elastic_model(std::shared_ptr<LinearElasticModel> emodel)¶: Set a new elastic model.

virtual void override_guess(double *const x)¶: Override the initial guess.

Public Static Functions

static std::string type()¶: String type for the object system.

static std::unique_ptr<NEMLObject> initialize(ParameterSet &params)¶: Return default parameters.

static ParameterSet parameters()¶: Initialize from parameter set.