J2 creep¶

Overview¶

This interface specializes a generic creep rate model to $J_2$ flow. The model creeps in the direction of the deviatoric stress and the scalar creep rate is defined by an additional interface. The creep rate for these types of models is then

$\dot{\bm{\varepsilon}}^{cr} = \dot{\varepsilon}^{cr}\left(\sigma_{eff}, \varepsilon_{eff}, t, T \right) \frac{\operatorname{dev}\left(\bm{\sigma}\right)} {\left\Vert \operatorname{dev}\left(\bm{\sigma}\right) \right\Vert}$

with the scalar creep rate a function of effective stress

$\sigma_{eff} = \sqrt{\frac{3}{2} \bm{\sigma} : \bm{\sigma}},$

effective strain

$\varepsilon_{eff} = \sqrt{\frac{2}{3} \bm{\varepsilon} : \bm{\varepsilon}},$

time, and temperature.

Class description¶

class J2CreepModel : public neml::CreepModel ¶

J2 creep based on a scalar creep rule.

Public Functions

J2CreepModel(ParameterSet &params)¶: Parameters: scalar creep rule, nonlinear tolerance, maximum solver iterations, and a verbosity flag

virtual void f(const double *const s, const double *const e, double t, double T, double *const f) const¶: creep_rate = dev(s) / ||dev(s)|| * scalar(effective_strain, effective_stress, time, temperature)

virtual void df_ds(const double *const s, const double *const e, double t, double T, double *const df) const¶: Derivative of creep rate wrt stress.

virtual void df_de(const double *const s, const double *const e, double t, double T, double *const df) const¶: Derivative of creep rate wrt strain.

virtual void df_dt(const double *const s, const double *const e, double t, double T, double *const df) const¶: Derivative of creep rate wrt time.

virtual void df_dT(const double *const s, const double *const e, double t, double T, double *const df) const¶: Derivative of creep rate wrt temperature.

Public Static Functions

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

static std::unique_ptr<NEMLObject> initialize(ParameterSet &params)¶: Initialize an object from a parameter set.

static ParameterSet parameters()¶: Return the default parameters.

J2 creep¶

Overview¶

Scalar creep models¶

Class description¶