Numerical investigation on the interlayer surface strength effects in carbon/epoxy composite laminates subjected to low-velocity impact

The Hashin failure model and the 3D progressive damage method-based user material subroutine are employed to characterize the impact damage characteristics of composite layer, and surface based cohesive behaviour are introduced to characterize the interlaminar mechanical property in this paper. The dynamic response process of the carbon/epoxy composite laminates subjected to low-velocity impact load under different interlayer surface strength conditions are simulated, and the effects of interlayer interface strength on the ballistic property of composite materials are emphatically analysed. Results show that the impact dynamic response of composite laminated plates is a process of stress waves propagation, reflection, and interference between layer and layer. The kinetic energy dissipation of bullet varies depending on the interlayer surface strength of carbon/epoxy composite laminates. The kinetic energy absorbing performance of carbon/epoxy composite laminates is directly altered by the interlayer surface strength. The interlayer surface strength of laminates also directly impacts of the elastic strain energy carbon/epoxy composite and the kinetic energy dissipation of bullet in laminates failure. Namely, the transformed form of the bullet kinetic energy is affected by the interlayer surface strength significantly. In general, the interlayer surface strength presents a significant role on whether the failure form, the contact force, the kinetic energy dissipation process, the elastic strain energy composite laminates or the kinetic energy dissipation of bullet in laminates failure during the impact process.