Tensile Loading Rate Effect on Open-Hole Tensile Strength and Failure Mechanism of Polymer Composites

Glass fiber reinforced polymer composite used in advanced engineering exercise as a frame in the aviation and automobile industries is often exposed to circular holes to connect different components through joints such as a bolt joint. In this article, the tensile strength of symmetric GFRP laminates with an open hole, and its failure mechanism under uniaxial varying tensile loading rate (1, 10, 50, and 100 mm/min) was investigated. The specimens were produced using the hand-lay-up process. Samples were prepared in compliance with the ASTM D5766 standard and tested with a 50 KN load cell on a universal Hounsfield H50KS testing machine. A numerical model was developed with shell model 3D deformable and meshed with the S4R element. Numerical results were compared with experimental results. Results suggest that the maximum tensile strength of composite specimens with open hole increased as the loading rate increased, and the debonding of fiber is a highly dominant failure mechanism as compared to other failures. The maximum tensile strength of specimens with a higher loading rate (100 mm/min) is maximum and is comparatively 15.04% greater than in slower loading rate of 1 mm/min. The experimental data reveal that rate-dependent constitutive relationships are helpful in modeling polymer composites and are used to estimate the effective failure response of composites.