Linear kinematic hardening

Overview

This object implements simple linear kinematic hardening. The backstress is defined as

\mathbf{X} = -H \bm{\chi}.

The model requires a length 6 history variable (\bm{\chi}) and maps to a length 6 backstress (\mathbf{X}).

Warning

All of the NEML yield surfaces assume the opposite of the standard sign convention for isotropic and kinematic hardening. The hardening model is expected to return a negative value of the isotropic hardening stress and a negative value of the backstress.

Parameters

Parameter

Object type

Description

Default

H

neml::Interpolate

Linear hardening constant

No

Class description

class LinearKinematicHardeningRule : public neml::KinematicHardeningRule

Simple linear kinematic hardening.

Public Functions

LinearKinematicHardeningRule(ParameterSet &params)

Parameter is the linear hardening coefficient.

virtual void q(const double *const alpha, double T, double *const qv) const

q = -H * alpha[:6]

virtual void dq_da(const double *const alpha, double T, double *const dqv) const

Derivative of the map.

double H(double T) const

Getter for the hardening coefficieint.

Public Static Functions

static std::string type()

String type for the object system.

static std::unique_ptr<NEMLObject> initialize(ParameterSet &params)

Initialize from a parameter set.

static ParameterSet parameters()

Default parameters.