Hello.

This is Sungho.

I have a quick question.

In the manual of ASPECT, stress tensor is defined by tau + p (here tau is 2*eta*strain 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?

Thanks