On the decreasing flexural modulus of glass/vinylester composite beams up to failure state

Abstract

The comparison of the failure state for composite laminates under bending and tensile loads is a well-known issue which has been intensively discussed in the literature. The scope of the current work is to investigate the appropriate method of the flexural modulus of the composite laminates by the aid of experimental and numerical approach. The primary objective of this study is to compare the experimental measurements of the elastic modulus of the composite laminates under the tensile and flexural tests. The numerical study is performed through progressive damage analysis (PDA) approach which is verified by simulation of the tensile specimens. This procedure is then used to predict the failure of the beam specimens under three-point-bending (3PB) test. Both interlaminar and intra-laminar damages are included in the developed models. The first type of damage is examined based on the continuum damage mechanics (CDM) approach and the second one based on the virtual crack closure technique (VCCT). The variation of the flexural modulus and ultimate strength of the composite beams is considerably depends on loading types and lay-up configurations. In this study, it is proven that the strain-based failure criterion can predict the realistic failure mode of the composite beams in consistency with the ultimate strains which was obtained from a simple tensile test.