Effect of quasi-static and intermediate strain rates on the tensile properties of hybrid polymer composites

This study presents the results of an investigation on the tensile behaviour of hybrid polymer composites under different strain rates. Glass/carbon, aramid/carbon, glass/aramid, and glass/aramid/carbon hybrid laminates were produced using vacuum assisted resin transfer molding method with epoxy resin system. Uniaxial tensile testing was performed to determine the tensile strength, modulus and failure strain of the hybrid laminates under quasi static (0.001 s ^‒1) and intermediate (5 and 10 s ^‒1) strain rates. Tensile strength and elastic modulus of hybrid composites increased with increasing the strain rate. Hybrid laminates with glass fibre were more sensitive to the strain rate. Carbon layers located at the centre of the hybrid laminates resulted in increased tensile strength, indicating the major role of stacking sequence on the behaviour of hybrid composites. Scanning electron microscope (SEM) was used to examine the fracture surfaces of the laminates. The extent of damage propagation was significantly broader at intermediate strain rates.