Test Defined Hyperelastic Materials

[lindejos]

Hi All,

I am working on simulating a really soft elastomer using the hyperelastic methods. I am finding that it has a lot of trouble if you apply stresses that are outside the test window, as if most of the fitting curves blow up in extrapolation.

I think using the second order polynomial is a bad idea, shouldn't they have a third order polynomial fitting option for hyperelastic materials? Can anybody offer some guidance?

This is my test data

strain stress (Pa)
0.05 13789.51456
0.1 34473.7864
0.15 131000.3883
0.2 275790.2912
0.25 430922.33
0.3 586054.3688
0.35 682580.9708
0.4 786002.33

 

[dr_gallup]

You really should not operate an analysis outside the measured data if possible. If you want a different type of extrapolation then do it yourself and add it to the test data.