High-velocity impact behaviour of curved GFRP composites for rail vehicles: Experimental and numerical study

Abstract

This study aims to explore the projectile impact behaviour of curved glass fibre reinforced plastics (GFRP) composites for rail vehicles through experimental and numerical methods. Quasi-static material tests were firstly carried out to obtain the tensile, compression, shear and bending properties. Then, high-velocity impact tests under different velocities were conducted for curved GFRP plates, which were cut from hood covers of a rail vehicle. The residual velocity of the projectile, the failure modes and the energy absorption of the composite targets were analysed. The classical Lambert-Jonas equation was used to predict the critical perforation velocity, which was also verified by the following finite element (FE) simulation in LS-DYNA. Based on the validated FE model, the effects of the impact velocity (65.14–152.22 m/s), target thickness (2 mm–8 mm) and impactor shape (flat, blunt, hemisphere and sphere) on the high-velocity impact performance of the target were studied. The results showed that the predicted critical perforation velocity of the curved GFRP plate with thickness of 6 mm was about 101.98 m/s in this study, and only local damages were observed near the trajectory. Increasing the thickness of the GFRP plate can improve its anti-penetration capability, however, the 4-mm plate possesses the highest specific energy absorption among the thickness of 2 mm–8 mm. Compared to the sharp impactors, the flat impactor resulted in the highest peak force of 260.39 kN and the maximum specific energy absorption of 502.65 J in the curved GFRP plates with thickness of 6 mm, due to the shear failure mechanism and the formation of embolism.