Chapter 5.15 - Correlation of the bridging model predictions of the biaxial failure strengths of fibrous laminates with experiments

Abstract

This chapter presents the bridging micromechanics model, which is combined with the classical lamination theory to predict the progressive failure strengths or the entire stress strain curves of a set of typical polymer resin based composite laminates subjected to different biaxial loads. The predictions are performed only using the constituent fiber and resin properties and the geometric parameters of the laminates specified independently. Comparison of the predictions with the experimental measurements provided by the failure exercise organizers is carried out. The prediction efficiency is also shown by correlating the predictions with the experiments. As a whole, the overall correlation between the theory and the experiments is reasonable. The chapter provides some additional comments regarding the applications of the bridging model to the simulation of the ultimate behavior of fibrous laminates. Comparison of the predictions of each other with and without thermal residual stresses is also made. For most of the present epoxy resin based composites, the effect of the thermal residual stresses is grossly insignificant. Thus, a general conclusion may be that in most cases the thermal residual stresses can be neglected for a thermoset polymer resin based composite.