This is Sungho.
I have a quick question.
In the manual of ASPECT, stress tensor is defined by tau + p (here tau is 2etastrain rate) in p. 476.
I have checked this expression in stress.cc (~/aspect/source/postprocess/visualization).
I think total stress should be defined by either “- tau + pI” or “tau - pI”?!
If we follow the present expression (tau + p ) for stress tensor, laterally outward velocity_x (tension) in 2D makes compression because positive strain increases total stress_xx.
How do you think?