GetDampTangent method question

rouyuan · Post by **rouyuan** » Mon Sep 10, 2018 5:32 am

Dear all,
I am building a new material which will need to use getDampTangent method in the source code. I used (∂ stress)/ (∂ strainrate) to derive this value. My question is in getDampTangent method, whether should the exact value be returned or the absolute one? Since I checked the viscous material source code, it seems to return the absolute value and why? Thanks a lot！
Regards