Experimental investigations on the repeated low velocity impact and compression-after-impact behaviors of woven glass fiber reinforced composite laminates

In this paper, the repeated low velocity impact responses and compression-after-impact (CAI) behaviors of woven glass fiber-reinforced composite laminates were studied at the same total impact energy. Three types of impact energies, 30, 40, and 60 J, were chosen for the repeated impact tests relative to the single 120 J impact event. The impact behaviors including impact contact force-displacement and energy-time curves during the impact testing were recorded. The variations of the impact mechanical characteristics such as peak impact force, maximum displacement, and energy absorption were evaluated. The methods of visual inspection and stereo microscope were applied to identify the damage morphology of the impacted laminates. The damage accumulation was evaluated employing the absorbed energy fraction and normalized maximum displacement. It was found that the influences of impact energy on the repeated impact mechanical response are more remarkable than that of the impact number, and the impact events with fewer impact numbers cause more damage to the laminates for the same accumulative impact energy. Furthermore, the load-displacement and the CAI strength versus impact number curves were compared for the CAI testing. The ultimate load and the resulted CAI strength decrease with the increase of impact number owing to the influence of damage accumulation in repeated impacts.

Automated summary

This paper investigates the repeated low velocity impact responses and compression-after-impact behaviors of woven glass fiber-reinforced composite laminates at the same total impact energy. The influence of impact energy on the mechanical response is more significant than the impact number, and fewer impact numbers cause more damage for the same accumulative impact energy.