IsoJ2¶

Overview¶

This is the isotropic-only version of IsoKinJ2. It implements standard $J_2$ plasticity with the yield function of

$f\left(\bm{\sigma}, \mathbf{q}, T\right) = J_2\left(\bm{\sigma}\right) + \sqrt{\frac{2}{3}}Q J_2\left(\mathbf{Y}\right) = \sqrt{\frac{3}{2} \operatorname{dev}\left(\mathbf{Y}\right): \operatorname{dev}\left(\mathbf{Y}\right)}.$

It assumes a “stress-like” history vector of

$\mathbf{q}=\left[\begin{array}{c}Q\end{array}\right]$

where $Q$ is the isotropic hardening stress.

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¶

None.

Class description¶

class IsoJ2 : public neml::IsoFunction<IsoKinJ2>¶

Just isotropic hardening with a von Mises surface.

Public Functions

inline IsoJ2(ParameterSet &params)¶: No actual parameters.

Public Static Functions

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

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

static ParameterSet parameters()¶: Return default parameters.