A second version of Yamada-Sun criterion more adapted to fabrics is proposed. The “tape” version of Yamada-Sun criterion is calculated in two directions, and the worst direction is considered for failure. The failure index is calculated as follows:
The allowables and depends on the signs of and respectively. Ply passes the failure criterion if the two following conditions are satisfied:
The reserve factor is calculated as follows:
and the strength ratio is given by:
This criterion is referred to as “YamadaSun_b” in FeResPost.