Three-dimensional failure criteria for fiber-reinforced laminates

This paper proposes a new fully three-dimensional failure criteria for polymer composites reinforced by unidirectional fibers. Existing failure criteria based on three-dimensional stress states are revisited and their limitations and pitfalls are identified. A new set of failure criteria for both longitudinal and transverse failure mechanisms where the effect of ply thickness on the material strength is accounted for is proposed. The accuracy of the failure criteria is assessed by comparing the analytical predictions with existing experimental data obtained under multiaxial stress states. A good agreement between the predictions and experimental data is generally observed.