Hello, Everyone

  Recently I met one confused question while doing the stress relasation analysis of elastomers.

It is observed that the elastomer with prony series under static step show the higher stiffness than the elastomer without prony series. Below is the comparison of their contact force at Y dirction.

But the result changed when I change the step setting from the static to vicosity step.  Meanwhile the time period is defined to 10000 s.  I found that the value under vicosity step is same to  the value of elastomer without Prony series at static step.

   So we got an interesting conclusion that we cannot see the real stress relaxation while applied the prony series into the rubber as the initial contact force has been increased by a lot.

  Could you help explain this issure or show some suggestions ? Many thanks.