Examination of low‐velocity impact and mechanical properties after impact of fiber‐reinforced prepreg composites

Fiber‐reinforced prepreg composites are considered to be the most promising materials for aerospace applications. However, these composites are susceptible to impact during in‐service phases. The impact can cause various types of damage, such as matrix cracks, delamination and fiber breakage, thereby considerably decreasing their mechanical properties. In this study, a series of experiments were carried out to investigate the LVI characteristics. The impact damage characteristics of the fiber‐reinforced prepreg composites were examined; the influencing factors and rules of impact damage were investigated; and the damage process and failure mechanism were revealed. X‐ray 3D computed tomography was employed to examine the internal damaged state of the fiber‐reinforced prepreg composites. An experimental study was carried out to investigate their compression after impact performance. The results indicated that impact energy mainly affects damage failure. With increasing impact energy, the impact contact time decreases, while the impact force fluctuation increases. The damage zone was spherical, and the damaged area increased with energy. The impact damage led to the sharp decrease in the remaining compressive strength and stiffness of the material, and the residual compression strength and stiffness were decreased to 62.25 and 76.6%, respectively. POLYM. COMPOS., 40:2154–2164, 2019. © 2018 Society of Plastics Engineers