# Contact pressure on hyperelastic material

**URL:** <https://calculix.discourse.group/t/contact-pressure-on-hyperelastic-material/2265>\
**Category:** Uncategorized\
**Created:** [May 12, 2024, 10:29am UTC](https://calculix.discourse.group/t/contact-pressure-on-hyperelastic-material/2265 "2024-05-12T10:29:41Z")\
**Posts on this page:** 1\
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**Author:** ![Disla](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/disla/32/3548_2.png) [@Disla](https://calculix.discourse.group/u/Disla)\
**Post date:** [May 12, 2024, 9:00pm UTC](https://calculix.discourse.group/t/contact-pressure-on-hyperelastic-material/2265/4 "2024-05-12T21:00:38Z")

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Hi JuanP74,

I’m now considering if this problem could be related with this post.

> [@\*dynamic - weird results](https://calculix.discourse.group/t/dynamic-weird-results/2266/5):
>
> when I am reducing the load, result is similar. But is kinda strange thing. One degree of freedom means that the mass can’t turn left or right. Newton’s law stay the same during motion. It means that the motion is under bifurcation and \*dynamic card is catching something else. Never saw it before. \*CLOAD,AMPLITUDE=StartAndStop 3,1,0.1 What about \*MASS card? Is it working now for all methods? \*\* based on example spring1.inp \*NODE,NSET=NALL 1,0.,0.,0. 2,1.,0.,0. \*ELEMENT,TYPE=SPR…

There are undelaying springs involved in contact.  
If some of them snap, the contact pressure could show uneven contact stresses. I say that because hyperplastic materials involve larger strains (clearance=amplitude).

I tried to check this point on compression only support, but at that time I wasn’t able to set up the gapuni offset in Mecway.

If you have the adjust active, ¿Could you try to deactivated it and provide some initial clearance to see if the problem disappear?

Regards

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