Investigating the Behavior of Glass Fiber/Polyester Layered Composites Under Low-Velocity Impact

This study investigates the behavior of glass fiber/polyester layered composites under low-velocity impact conditions, focusing on optimizing layer configurations and fiber types to enhance impact resistance. Composites were fabricated using a combination of E-glass mat and woven glass fibers with orthophthalic polyester resin, employing the hand lay-up method. Impact tests were conducted using a drop hammer device. Key variables included the number of layers and fiber types, with impacts performed using flathead and hemispherical impactors. The results showed that increasing the number of layers significantly enhanced energy absorption and peak contact force. Specifically, five-layer samples exhibited a 351% increase in energy absorption and a 212% increase in peak contact force compared to two-layer samples. Mat fibers outperformed woven fibers, with mat-only samples absorbing 21.8% more energy and showing 5.8% higher peak forces. Additionally, flathead impactors generated 101% higher peak forces and caused more severe damage than hemispherical impactors. Observed failure modes included fiber breakage, matrix cracking, and delamination, all influenced by impact parameters and material characteristics. These findings provide valuable guidance for designing composite materials with improved resistance to impact, with potential applications in the aerospace, marine, and automotive industries.