Damage Mechanisms and Mechanical Behavior of Epoxy Composites after Low Velocity Impact

Abstract

This study provides a comprehensive review of existing research on the low velocity impact response, post-impact mechanical strength, and damage mechanisms of epoxy hybrid composites reinforced with fibers or fabrics. It focuses on the investigation of the influence of various factors on the impact damage mechanisms, such as matrix cracking, delamination, fiber breakage, and fiber pullout, which significantly reduce the residual mechanical properties of these composites. Herein, it is discussed the ways of optimizing impact response, post-impact mechanical properties, and resistance to damage by hybridization, incorporation of fillers into epoxy matrix, and insertion of metal wires between certain layers. This study reveals that the impact energy level, impact angle, impactor size, and shape significantly affect damage severity and energy absorption. The hybrid composites with specific fiber combinations and ply orientations can enhance impact resistance and post-impact mechanical strength. The combination of different fibers can offer tailored properties and improved impact behavior compared to pure fabric composites. By adding fillers to epoxy matrix and metal wires between certain plies, it can reduce residual deformations and damage degree. The natural fiber-reinforced epoxy composites exhibit high impact strength due to their fiber structure and can be a sustainable alternative to synthetic fibers.