In-plane shear failure properties of a chopped glass-reinforced polyester by means of traction–compression biaxial testing

We perform traction–compression biaxial testing in a chopped glass-reinforced polyester, applying in-plane perpendicular tensile–compressive loads to cruciform specimens. The purpose is to evaluate if this technique is suitable to perform shear tests and determine the shear strength and the shear failure strain of the composite. The failure properties obtained experimentally from this technique are compared with the analytical predictions of the Maximum stress, Maximum strain, Tsai-Hill and Tsai-Wu failure theories and the numerical results obtained by means of the Finite Element Method. The analysis is developed taking into account the different behaviour of the material under tension and under compression.