Mechanical properties and failure mode of thin-ply fiber metal laminates under out-of-plane loading

Abstract

In this study, fiber metal laminates (FMLs), which consisted of thin-ply prepreg and stainless steel layers with a ply thickness of 0.04 mm, were fabricated with the aim of suppressing the fiber breakage that decreases the compression-after-impact (CAI) strength. Then, static flexural tests of FMLs were conducted to investigate the effects of the number of metal layers on the failure mode and mechanical properties during static out-of-plane loading, and the results were compared with those of our previous impact and CAI tests. The results confirmed that the plastic deformation of metal layers improved the energy dissipation and thus failure occurred in a limited range of locations. Furthermore, the investigation of the in situ stress during flexural tests by finite element method (FEM) analysis revealed that a hybrid material that both suppresses ply failure and has a high modulus of the metal can be realized owing to the constraining effect of thin-ply laminates.