Abstract:
To enhance the low-velocity impact resistance of carbon fiber reinforced resin matrix composite (CFRP) honeycomb sandwich panels, four CFRP/aluminum laminated structures with similar surface densities were designed by adopting the concept of fiber-metal laminates (FML) for the face sheets of the honeycomb sandwich panel, and low-velocity impact tests were conducted using different impact energies. Through the development of a low-speed impact finite element model, the effects of different stacking sequences on stress propagation and the failure mechanisms of honeycomb sandwich structures were investigated. Additionally, the damage morphologies and ultimate loads of panels from various specimens were compared, and the energy absorption characteristics under different failure modes were analyzed. The research findings indicate that the lamination configuration of the panel significantly influences its mechanical properties. In terms of damage morphology, cracks in the surface aluminum layer propagate from the indentation towards the fiber ply direction, whereas the failure region in the surface CFRP layer exhibits brittle fracture along the fiber orientation. In terms of load-carrying capacity, the Al-CF laminate configuration exhibits the best performance, followed by the CF-Al-CF configuration. Compared with the pure CFRP panel honeycomb sandwich structure, the limit loads of these two laminate configurations were increased by 22.18% and 5.18%, respectively. Regarding energy absorption, when the panel remains intact, the FML panel honeycomb sandwich structure absorbs more energy than the CFRP panel honeycomb sandwich structure. When the panel undergoes penetration failure, the energy required for failure in the Al-CF, Al-CF-Al, and CF-Al-CF laminate structures is 33.6%, 19.6%, and 22.10% higher than that of the CFRP panel, respectively.