Question about Hysteretic material parameters

[omidgahremani]

Dear all,
how can we know exactly what is the usage of this parameters in hyseretic material command :
$pinchx pinching factor for strain (or deformation) during reloading
$pinchy pinching factor for stress (or force) during reloading
$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)
please send me a paper or text that can clear me with this subject.

[fmk]

the best way to learn about them is to play with them using some predetermined strain history.

[hysteresis]

Please refer to the link below to get an idea of each parameter:

https://opensees.berkeley.edu/OpenSees/ ... l/4052.htm