On the correlation between stiffness and strength properties of anisotropic laminates

This paper focuses on the analytical formulation of laminate-level failure criteria which are expressed (under a unified matrix formulation) in the framework of the first-order shear deformation theory (FSDT) in order to take into account the influence of the transverse shear stresses on the failure mechanisms. The proposed unified formulation relies on the utilization of the polar formalism generalized to the FSDT framework: in this background, all the considered criteria are stated in terms of tensor invariants. Furthermore, an important theoretical result is proven: the existence of a set of analytical relationships between the laminate strength and stiffness invariants.