Stress-strain model for the steel material that can consider the stiffness degradation and strength degradation?

[gooddaytogo]

Hello, everyone,

I am looking for a stress-strain model for the steel material that can consider the stiffness degradation and strength degradation and also this material model can be used in the fiber section. Are there any recommendations for it and which one is the best option for the steel material and the fiber section? Also are there any references or examples to help determine the model parameters for the steel material? Any suggestions are appreciated. Thanks.

[mhscott]

HystereticMaterial is often used for steel to capture stiffness and strength degradation. There should be many examples online.

[gooddaytogo]

HystereticMaterial is often used for steel to capture stiffness and strength degradation. There should be many examples online.

Thanks a lot for your reply. HystereticMaterial is very useful to model the stiffness and strength degradation. But I don't know how the following parameters influence the degradation:


$damage1 damage due to ductility: D1(mu-1)
$damage2 damage due to energy: D2(Eii/Eult)
$beta power used to determine the degraded unloading stiffness based on ductility, mu-beta (optional, default=0.0)


I don't know if you can provide some references about how these three parameters change the stiffness and strength. It would be better if there are some theoretical equations to quantify their influence. Any suggestions about these three parameters are appreciated.