Failure by Shear of Transversely Isotropic Laminae Off-Axis Loaded According to the EPFS-Criterion

Failure prediction of off axis loaded fiber composite laminae are given, according to a failure criterion for generally anisotropic solids introduced by the authors. The failure condition used assumes that for any anisotropic solid a safe triaxial loading path exists, namely the hydrostatic compression, and thus the failure surface must be open-ended. By appropriately formulating the failure criterion, it is shown that the geo metric representation of the failure surface in the principal stress space is an elliptic para boloid (EPFS). In this paper the predictions of the above criterion for plane stress failure loadings of off-axis laminae, especially for shear induced failure, are compared with exist ing experimental data and are shown to be in satisfactory agreement.