Effect of temperature on the low-velocity impact behavior of composite sandwich panels

Composite sandwich panels constructed from glass-fiber-reinforced facesheets surrounding both foam-filled and nonfilled honeycomb cores are impacted using a drop-weight impactor at three energy levels and three temperatures. The effects of core material, temperature, and impact velocity on the absorbed energy, peak impact force, and damage mechanisms were studied. The foam-filled samples were subsequently subjected to four-point bend tests to investigate the effect of impact velocity and temperature on the damage tolerance and residual strength of the composites. It was found that the temperature can have a significant effect on the energy absorbed and maximum force encountered during impact, although the effect of the impact temperature on the residual bending stiffness and strength of the composites was mixed. In addition, the nature of the core material greatly influenced the damage mechanisms and impact force transfer in the honeycomb sandwich composites.