Default compressibility coefficients for some Hyperplastic materials (at least OGDEN N3 ) are unit dependent and lead to different material response depending on if one uses MPa or Pa as main unit system. The reason seems that default D2 and D3 are built as powers of D1. (FILE “hyperelastics.f”.)
D2=D1^2
D3=D1^3
The issue has been exposed and debated at the end of this post published in the ccx forum:
Hello ,
Default compressibility coefficients for some Hyperplastic materials (at least OGDEN N3 ) are unit dependent and lead to different material response depending on if one uses MPa or Pa as main unit system. The reason seems that default D2 and D3 are built as powers of D1. (FILE “hyperelastics.f”.)
D2=D1^2 D3=D1^3
The issue has been exposed and debated at the end of this post published in the ccx forum:
https://calculix.discourse.group/t/contact-pressure-on-hyperelastic-material/2265/35