Prediction of failure in unsaturated polyester reinforced by plain weave glass fabric

Polyester/glass fiber is probably by far the most commonly used composite. This paper presents the results of an investigation on the failure of this composite made of plain weave glass fabric. A recently proposed sub-plies model was utilized to predict the failure strengths of the fabric composite after shear deformation of the interlaced yams, induced by the forming process. A procedure for the determination of the equivalent on-axis tensile and compressive strengths of the constituents plies is also proposed to take into account of fiber undulation effect on mechanical properties. The predicted compressive and tensile strengths are compared with experimental measurement as a function of the deformation angle of the interlaced yarns. Furthermore, the onset of damage was also compared with the initial failure of the sub-plies model The predicted results are in good with the experimental data.