Simulate with complex geometries and complex physics
%ind_Sn(3)%
Stress tensor times boundary normal, i.e. stresses acting on surface, unit=Pa
z-component of \begin{align} \left( {\bf S}_{visc}+{\bf S}_{solid} - (p_{hyd}+p_{dyn}) {\bf I} \right) \cdot {\bf n}\end{align}