The effect of stacking sequence and temperature on the mechanical and low velocity impact response of glass/epoxy laminates

This paper demonstrates both low velocity impact and mechanical test results of glass/epoxy composites at room and high temperatures. Square specimens of glass/epoxy composite laminates with lay-ups [0/0/90]s, [90/0/0]s, [0/90/45]s were subjected to low velocity impact energy range of 4 J to 22 J using an impact test machine at temperatures of 20°C, 50°C and 90°C. Load-defection and energy profile diagrams were plotted for each stacking sequence and temperature. After impact, a high-intensity light was used to measure the projected delamination areas in the impacted glass/epoxy composite laminates. In order to investigate effects of temperature on mechanical properties and impact resistance, mechanical tests were also performed using unidirectional glass/epoxy composite plates composed of eight plies produced according to ASTM Standards. In addition, to understand the contribution of thermal residual stresses occurring during and after manufacturing of composite laminates on impact-induced delamination, SX and SY stresses in the composite laminates at 20, 50 and 90°C were determined by using ANSYS software. It can be concluded from this study that temperature has significant effects on the impact behaviour and mechanical properties of glass fibre-reinforced epoxy composite laminates. Besides, an increase in temperature decreases both the delamination area and the contribution of thermal residual stresses on delamination under the same impact loading