Effect of patch thickness and size on the low-velocity impact of patch-repaired CFRP composite laminates for rail vehicles

Abstract

Abstract In this study, a high-strength carbon fiber reinforced composite laminate for rail vehicles was machined as a perforated sample and repaired with a patch of the same material. The response of the repaired laminate to a low-velocity impact with an energy of 30 J was investigated through experiments and simulations. The finite element simulation model was established in Abaquas/Explicit. The model integrated the progressive damage model based on the Hashin failure criterion, which can simulate the intralaminar damage of the fiber and the matrix. The cohesive zone model was used to simulate the delamination damage. According to the finite element analysis results, the mechanism and process of impact damage of the repaired laminates were analyzed. Based on the validated finite element model, the effect of patch size and thickness on impact damage was investigated. The reduction in patch size had little effect on the impact response, but could change the damage mechanism of the repaired laminate and increase the risk of damage to the mother panel. Repair laminate with a patch thickness of 0.6 mm was not able to resist impact and was penetrated.