Experimental Compression Behaviour and Failure Mechanisms of Woven E-Glass and Carbon Fiber Composite Laminates for Lightweight UAV Structural Applications

Fiber-reinforced polymer composites are increasingly used in lightweight aerospace structures due to their high strength-to-weight ratio, excellent corrosion resistance, and superior mechanical performance compared with conventional metallic materials. Among these materials, glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP) composites have gained widespread attention for use in unmanned aerial vehicle (UAV) structures, where structural efficiency, durability, and cost-effectiveness are critical design considerations. Understanding the compressive behaviour and failure mechanisms of composite laminates is therefore essential for ensuring structural reliability and safe operation in aerospace applications. This study presents an experimental investigation of the compressive behaviour of woven E-glass fiber-reinforced epoxy and carbon fiber-reinforced epoxy composite laminates. Rectangular specimens were prepared from commercially manufactured composite laminate plates with approximate dimensions of 100 mm × 95 mm and a laminate thickness of approximately 1.5 mm. Compression tests were performed using a universal testing machine under displacement-controlled loading conditions until structural failure occurred. The results revealed significant differences in the mechanical response of the two composite systems. Carbon fiber-reinforced laminates exhibited considerably higher stiffness and compressive load capacity due to the higher modulus of carbon fibers. However, carbon fiber specimens exhibited brittle failure, characterized by sudden fiber fracture and a rapid loss of load-carrying capacity. In contrast, E-glass laminates exhibited lower stiffness but showed more progressive damage, including matrix cracking and fiber buckling, prior to final failure. These findings highlight the trade-off between stiffness and damage tolerance in fiber-reinforced composites and provide useful experimental insight into the compressive performance of commonly used aerospace composite materials. The results contribute to the development and optimization of lightweight composite structures for UAV structural applications.