Biaxial strength of cross-ply carbon fiber-reinforced composite laminates fabricated by lapped molding technique

A failure criterion must be considered for each failure mode and parameters of the model determined in each case. In this study, a failure criterion was developed by introducing the notion of equivalent biaxial strength under biaxial loading of tension and torsion. The experimental results showed that the equivalent biaxial strength has a power-type relation to a parameter, cos ψ. The failure strength under biaxial loading can be predicted as a function of tensile strength, torsional strength and biaxial ratio. Scattering of the experimental data can be predicted using a Weibull distribution function and the concept of equivalent biaxial strength. The model should accurately predict the biaxial strength of general laminated composite materials.