An experimental study on the low energy impact behavior of different number of layer e-glass/epoxy composites

Composite materials are increasingly used in structural applications due to the high strength-to-weight ratio, corrosion resistance, and design flexibility they offer; however, susceptibility to impact damage remains a critical concern, particularly in layered configurations. In the present research, low-velocity impact experiments were performed on 8-layer and 16-layer unidirectional E-glass/epoxy composite plates with [+45/-45/90/0]s and [+45/-45/90/0]2s stacking sequences, which were manufactured using the vacuum-assisted hand lay-up method, at impact energy levels of 10, 20, and 30 J. Findings indicated that a rise in impact energy resulted in an increase in maximum contact force and energy absorption for both 8-layer and 16-layer composite plates, with no noticeable change in bending rigidity. At the same energy level, an increase in the number of layers enhanced the maximum contact force and bending rigidity of the composite plates, whereas displacement and the amount of energy absorbed by the material decreased. For all energy levels, the damage observed in the 8-layer composite plates spread over a wider area compared to the damage in the 16-layer plates.