Enhancing Impact Energy Absorption, Flexural and Crash Performance Properties of Automotive Composite Laminates by Adjusting the Stacking Sequences Layup

In response to the high demand for light automotive, manufacturers are showing a vital interest in replacing heavy metallic components with composite materials that exhibit unparalleled strength-to-weight ratios and excellent properties. Unidirectional carbon/epoxy prepreg was suitable for automotive applications such as the front part of the vehicle (hood) due to its excellent crash performance. In this study, UD carbon/epoxy prepreg with 70% and 30% volume fraction of reinforcement and resin, respectively, was used to fabricate the composite laminates. The responses of different three stacking sequences of automotive composite laminates to low-velocity impact damage and flexural and crash performance properties were investigated. Three-point bending and drop-weight impact tests were carried out to determine the flexural modulus, strength, and impact damage behavior of selected materials. Optical microscopy analysis was used to identify the failure modes in the composites. Scanning electron microscopy (SEM) and C-scan non-destructive methods were utilized to explore the fractures in the composites after impact tests. Moreover, the performance index and absorbed energy of the tested structures were studied. The results showed that the flexural strength and modulus of automotive composite laminates strongly depended on the stacking sequence. The highest crash resistance was noticed in the laminate with a stacking sequence of [[0, 90, 45, −45](2), 0, 90](S). Therefore, the fabrication of a composite laminate structure enhanced by selected stacking sequences is an excellent way to improve the crash performance properties of automotive composite structures.