Experimental and numerical analysis of low velocity impact on a preloaded composite plate

An experimental and numerical study on the influence of biaxial preloading on the low velocity impact performance of E-glass/epoxy-laminated composite plates was conducted. For this aim, an experimental device was developed to apply the load in two perpendicular directions. Three preload cases, representative of actual structures were selected, biaxially tension, compression and, tension-compression (shear) loading cases. The samples were produced from unidirectional reinforced E-glass and epoxy, by using a hand lay-up technique. Laminated E-glass/epoxy with stacking sequence [0/90]2s, dimensions were 140 × 140 mm2 and a thickness of 2 mm for the samples used. Finite element analysis (FEA) was developed, using Hashin failure criteria for the composite material, and material models implemented by a User Material Subroutine into ABAQUS®/explicit software, in order to simulate the failure mechanisms and force–time histories. Force–time and energy–time data were obtained by means of user material subroutine from the finite element model. The finite element results showed a good correlation to the experimental data in terms of force–time, energy–time graph or failure in composite plate, although these numerical results strongly depended on simulation parameters like mesh size or the number of element.