Influence of impactor shape on low-velocity impact behavior of fiber metal laminates combined numerical and experimental approaches

Abstract

Abstract Fiber metal laminates (FMLs) are fabricated with composite laminates and metallic alloys. This paper systematically investigates the influence of impactor shape on the low-velocity impact response of FMLs by combining the experimental and numerical methods. A series of impact experiments are conducted to study the low-velocity impact behavior of different FMLs under various impactor shapes and impact energies. The commercially available digital image correlation measuring system is applied to scan the exterior deformations of FMLs after impact. Subsequently, a progressive damage model based on the Hashin and Yeh delamination failure criteria is employed to characterize the damage evolution and failure mechanisms of composite materials through a user defined subroutine (VUMAT) in ABAQUS/Explicit. The study's results demonstrate that the impact behavior of FMLs is strongly dependent on impactor shape, impact energy and metal layer distribution. For the complete penetration case, the smooth perforation resulted from shear effect occurs in FMLs impacted by blunter impactor, while the petaloid cracks caused by tensile tearing damage appears for sharper impactor case in the process of penetration. The predicted results for different impact cases show a good comparison with experimental results in terms of impact loads, total absorbed energies and damage morphologies, which indicate that the numerical simulation could be a helpful tool to evaluate the impact response of FMLs.