The impact response of composite laminates based on fracture toughness stiffness degradation

Based on ABAQUS, a 3D finite element analysis model of damage of composite laminates under low-speed impact was established. By writing VUMAT subroutine, this paper uses strain-based 3d Hashin failure criterion to judge fiber failure. The bilinear stiffness degradation scheme based on fracture toughness of fiber constitutive model is adopted for stiffness reduction. This paper uses cohesive element to simulate the area between the layers. Traditional stress failure criterion and strain energy release rate was used to analyze the initiation and evolution of delamination damage. The effects of different stiffness degradation schemes on the response of laminated plates under low velocity impact are analyzed in this paper.