# Steel01 Material for Sensitivity
This command is used to construct a uniaxial bilinear steel material object with kinematic hardening and optional isotropic hardening described by a non-linear evolution equation (refer to http://peer.berkeley.edu).
```tcl uniaxialMaterial Steel01 $matTag $sigmaY $E $b <$a1 $a2 $a3 $a4> ```matTag |
unique material object integer tag |
E |
initial tangent stiffness |
sigmaY |
yield strength |
b |
strain-hardening ratio (ratio between post-yield tangent and initial elastic tangent stiffness) |
|
isotropic hardening parameters: (optional, default: no isotropic hardening) |
Note: For this material class, the sensitivity parameters can be: E, sigmaY, b, a1, a2, a3, a4