Crashworthiness capability of thin-walled fibre metal laminate tubes under axial crushing

Abstract

This study aims to evaluate the crushing behaviour of aluminium-glass fibre reinforced plastic (GFRP) with different layer configurations known as fibre metal laminate (FML) subject to dynamic loading conditions. The tubes were assembled to form 2/1 and 3/2 layout configurations. Resin and braided fiberglass sleeve were introduced as composite layer and sandwiched with two layers of aluminium tubes in forming 2/1 lay-up structure while a layer of composite and aluminium tube is added up alternately for 3/2 lay-up structure. These tubes were tested to evaluate the impact characteristics under low-speed axial impact loading. A finite element (FE) model was also developed and validated against the experimental results. In the numerical evaluation using a validated FE model, the internal energy of an aluminium tube was higher than the internal energy of a GFRP tube when the FML tube was progressively crushed. A series of parametric studies have shown that the increase in aluminium and GFRP wall thickness resulted higher specific energy absorption (SEA). The FML tube fold similar to the crush mode of outer tube material as when it is in its single tube form. All tube configurations were progressively crushed and unlikely to fail under catastrophic failure. FE model founds the aluminium tube layer is more dominant in energy absorption mechanism of the FML tube and increasing the number of tube layers improved crashworthiness significantly. From this discovery, a FML tube could be considered as a suitable lightweight candidate for energy absorbing applications with considerable crashworthiness capability.