Experimental and numerical investigations on dynamic behavior of CFRP laminates

Increased application of carbon fiber reinforced polymer (CFRP) composites to resist blast loadings necessitated investigating their dynamic behavior. It requires characterization of the CFRP laminates at high strain rates using split Hopkinson pressure bar or comparable device. In this investigation, tensile properties of the CFRP laminates subjected to high strain rates are studied experimentally and numerically. Experimental evaluation of tensile properties of the CFRP laminates using the Hopkinson bar is a tedious, time consuming, and costly exercise. Hence, upon conducting limited experimental evaluation, a numerical model is developed to characterize these composites at high strain rates. The developed numerical model of the Hopkinson bar technique is validated against the results obtained from the experiments conducted using crossbow system on the CFRP laminates. Full-scale tensile stress-strain curves are developed to study the effect of the strain rate on the ultimate tensile strength, elastic modulus, and energy absorption capacity of the CFRP laminates. It is observed that the CFRP laminates are sensitive to the strain rates and their ultimate tensile strength and energy absorption increases with the increase in the strain rate. Moreover, the effect of variation in thickness and length to width ratio for a constant stress pulse is insignificant.