I have a tetra mesh which is more or less spherical and I would like to quantify the shear stress in the tetra elements. Is there a way to calculate the forces tangentially to the surface of the mesh (when the surfaces of the individual elements are not parallel to the surface of the mesh, like it is the case in a tetra mesh)? Is it for example possible to establish some kind of spherical coodinate system in the center of my mesh and calculate the stress perpendicular to an axis that points into the center of that coordinate system?
