Hello,
In documentation r5.03.35, I read in second part of Eq.1:
(de/dt) = s/eta + (ds/dt) / 2G
If e is tensorial shear strain and eta the viscosity defined as the ratio of shear stress over engineering shear strain, I believe there would be "2 eta" instead of just "eta". Does it mean that eta in this document (and in the code) is the viscosity defined for tensorial shear strain, and not for engineering shear strain ?
This is quite important in practice, because knowing the shear relaxation time, the conversion to a viscosity for code aster would be different by a factor of 2 depending on the definition.
I appreciate any insights you can share. Thanks!
