Inelastic isolator material model

[civilengineering]

Hi everyone

I want to model a base isolated structure with inelastic isolator. The material model of isolator is bilinear such that the first line (linear region) matches on stress axis until yield point (Q) and the second line (inelastic region) starts from Q point (Q= strength of the isolation system, namely force at zero displacement) and continues with kb stiffness. I used several material models including Hysteretic material, Bouc Wen, MultiLinear models to this purpose, but the seismic responses obtained from time history analyses are not reasonable.
Is there anybody who can kindly help me on modeling above mentioned isolator behavior ?

Thanks so much

[nyangi]

I am starting doing the same model please share with me if you got something