Interlaminar shear strength of marine composite laminates: Tests and numerical simulations

This paper deals with an experimental/numerical comparison of the interlaminar shear stress in typical marine composite laminates manufactured according to two different fabrication processes, namely vacuum infusion and pre-impregnated lay-up. Experimental tests were carried out at the Marine Structures Testing Lab of the University of Genova. Actually, among widely applied empirical formulations for the characterization of composites suggested by Classification Societies rules, the ones for the interlaminar shear strength appear the most scattered because of the complexity in assessing failure phenomena. Composite manufacturers generally carry out rather extensive tests for the complete characterization of the laminates. Due to non-linearities involved in the captioned study, the support of nonlinear numerical models was required. The aim of the comprehensive use of numerical approaches is the reduction of time-consuming and expensive experimental campaigns. Three different FE modeling strategies are proposed in order to verify the reliability of the numerical results in comparison with experimental targets. The merits and shortcomings of each are discussed, also comparing different types of finite element formulations and mesh refinement sensitivity.