3.1.5.25. Hardening Material

This command constructs an elastoplastic uniaxial material with combined isotropic and kinematic hardening. Also accepted as Hardening2.

uniaxialMaterial Hardening $matTag $E $sigmaY $H_iso $H_kin <$eta>

Argument	Type	Description
$matTag	integer	unique material tag
$E	float	initial stiffness
$sigmaY	float	yield stress
$H_iso	float	isotropic hardening modulus
$H_kin	float	kinematic hardening modulus
$eta	float	optional damping tangent (default 0.0)

The post-yield slope is \(E(H_{iso}+H_{kin})/(E+H_{iso}+H_{kin})\). To match a Steel01-style hardening ratio \(b\) with kinematic hardening only (\(H_{iso}=0\)), use \(H_{kin} = bE/(1-b)\) (equivalently \(bE = EH_{kin}/(E+H_{kin})\)); see Elastoplastic Calibration.

Example

1. Tcl Code

uniaxialMaterial Hardening 1 3000.0 30.0 100.0 200.0

2. Python Code

ops.uniaxialMaterial('Hardening', 1, 3000.0, 30.0, 100.0, 200.0)

Code Developed by: Michael H. Scott