Linear vicous flow rule

Overview

This simple model provides a linear viscous response of the type

$\dot{\gamma} = \frac{3}{2} \frac{f\left(\bm{\sigma}, \mathbf{0}, T\right)}{\eta\left(T\right)} \mathbf{g}_{\gamma} = \frac{\partial f}{\partial \bm{\sigma}} \left( \bm{\sigma}, \mathbf{0}, T \right)$

where $f$ is a flow surface

The model does not maintain internal variables.

Parameters

Parameter	Object type	Description	Default
`surface`	`neml::YieldSurface`	Flow surface interface	No
`eta`	`neml::Interpolate`	Drag stress	No

Class description

class LinearViscousFlow : public neml::ViscoPlasticFlowRule 

Linear viscous perfect plasticity.

Public Functions

LinearViscousFlow(ParameterSet &params): Parameters: just a surface and a drag stress.

virtual void populate_hist(History &hist) const: Populate a blank history object.

virtual void init_hist(History &hist) const: Initialize history at time zero.

virtual void y(const double *const s, const double *const alpha, double T, double &yv) const: Scalar strain rate.

virtual void dy_ds(const double *const s, const double *const alpha, double T, double *const dyv) const: Derivative of y wrt stress.

virtual void dy_da(const double *const s, const double *const alpha, double T, double *const dyv) const: Derivative of y wrt history.

virtual void g(const double *const s, const double *const alpha, double T, double *const gv) const: Flow rule proportional to the scalar strain rate.

virtual void dg_ds(const double *const s, const double *const alpha, double T, double *const dgv) const: Derivative of g wrt stress.

virtual void dg_da(const double *const s, const double *const alpha, double T, double *const dgv) const: Derivative of g wrt history.

virtual void h(const double *const s, const double *const alpha, double T, double *const hv) const: Hardening rule proportional to the scalar strain rate.

virtual void dh_ds(const double *const s, const double *const alpha, double T, double *const dhv) const: Derivative of h wrt stress.

virtual void dh_da(const double *const s, const double *const alpha, double T, double *const dhv) const: Derivative of h wrt history.

Public Static Functions

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

static std::unique_ptr<NEMLObject> initialize(ParameterSet &params): Default parameters.

static ParameterSet parameters(): Initialize from parameters.