The Tsai-Hill criterion is a quadratic criterion. The 3D version of this criterion has a failure index calculated as follows:
The allowables , and depend on the signs of , and respectively. Ply passes the failure criterion if
The Tsai-Hill failure index depends quadratically on the different components of the stress tensor. The reserve factor is calculated as follows:
(II.1.122) |
and the strength ratio is given by:
(II.1.123) |
This criterion is referred to as “TsaiHill3D” criterion in FeResPost.