Influence of in-plane preload on the impact behavior of composite sandwich panels

The impact behavior of sandwich panels subjected to in-plane uniaxial preloading is analyzed. The relevance of this study lies in the combined effects of the stresses due to the in-plane preloading and the stresses due to impact, which can cause damage and affect the mechanical behavior of the structure. A numerical model is proposed that can simulate several damage mechanisms in the sandwich structure, including both interlaminar and intralaminar damage, as well as the non-linear behavior of the foam core. The model has been validated using experimental results from previous works. A reference impact velocity was estimated that causes minor damage to the front face-sheet of an unloaded sandwich. The numerical model was then used to analyze the influence of in-plane uniaxial tensile and compressive loads applied to a sandwich panel subjected to impact. It is observed that the load has little effect on the maximum displacement of the projectile. However, the influence on rebound velocity, energy dissipated, and damage is significant. A change in the damage pattern with the in-plane preload is also observed, with the effect of the preload being more significant in compression, probably due to the buckling of the impact-damaged plies in the front face-sheet.

Influence of in-plane preload on the impact behavior of composite sandwich panels Articles