Hi Peter

Much appreciate for your suggestion. It is truly useful to solve the model.

This model could be the as-molded shape but I will ask my teacher tomorrow on the class.

You mentioned that the metal parts can be changed from Flexible to Rigid, but there are something turn to different I do not understand.

Could you explain how you adjust the contact/target faces?

The nylon bead and the steel steel wire I afraid they can not be contained together. The name "nylon tire cord" which is the important part for the air spring.

Right now my idea is use 2 step to solve the model:

step1: give the presure to 0.45 Mpa and find out the displacement ( from that point x=0) => F=KX

step2: add force(finally force should be 130000 N) to calculate the stiffness Kz(k=f/x)

THX

Wayne