Out of Plane (Z') Stress Tensor Components

Out of plane (Z') stress tensor components

Thin shells in Ansys LS-DYNA do not calculate the element through-thickness ( _Z' ) direct stress which will always be zero, although the through thickness shear terms ( _YZ' and _XZ' ) are calculated. Thus five of the six terms of the local stress tensor are used, giving:

This means that principal stresses will not necessarily lie in the plane of the shell.