The effect of short Kevlar fibers interfacial toughening on impact properties of carbon fiber/aluminum honeycomb sandwich panels

Due to the susceptibility of carbon fiber/aluminum honeycomb sandwich structures to interface damage under impact loading, their overall mechanical performance can be compromised, potentially leading to structural failure. This poses a severe risk to the safety of such structures in engineering applications. This study initially conducted low-velocity impact tests and post-impact compression tests on carbon fiber/aluminum honeycomb sandwich panels with both untoughened and short Kevlar fibers toughened interfaces, using four different impact energy levels (10 J, 20 J, 30 J, and 50 J). The experimental results indicated that the toughening with short Kevlar fibers significantly enhanced the impact resistance and residual compression performance of the sandwich panels. Subsequently, the impact test on the toughened specimen was simulated numerically and the experimental results were in good agreement with the numerical simulations. Finally, based on the numerical model, the study explored the influence of varying face sheet parameters on the impact resistance of short Kevlar fibers toughened carbon fiber/aluminum honeycomb sandwich panels. Layup quantity and layup angle have significant influence on the impact resistance of sandwich panels. With the increase of layup quantity, the impact resistance improves. In several layup angles, [0/45/90/-45/0/45] layering method shows the best impact resistance.