Numerical and experimental characterization of high-speed impact damage in CFRP unidirectional and cross-ply laminates

This paper aims at characterizing the high-speed impact damage behavior in CFRP unidirectional (UD) and cross-ply (CP) laminates. First, high-speed (~ 400 m/s) impact damage was introduced by collision of a flying steel sphere (projectile) to CFRP plates with the use of an electric heat gun. The surface and internal damages of the CFRP specimens were observed by using optical microscopy together with radiography. The damage process model was then established on the basis of the experimental result. Next, the dynamic finite element analysis was performed to simulate the damage process. Cohesive elements were introduced in the analysis to express the initiation and propagation of delamination while the maximum stress fracture criteria were employed to express another type of damage such as tensile, compressive and shear failure of the elements. Finally, the simulation was compared with the experimental results to understand the damage evolution mechanism.