Experimental study on mechanical behaviour and microstructural assessment of Kevlar/epoxy composites at liquid nitrogen temperature

Abstract

This present investigation has emphasised on understanding the mechanical behavior and progressive failure modes of Kevlar/epoxy reinforced laminated composites subjected to 3- point bend test at liquid nitrogen temperature (77K temperature). The tests were conducted on the woven fabric laminates with different loading speeds and characterized by scanning electron microscope (SEM). The effect of liquid nitrogen temperature on interlaminar shear strength (ILSS) of Kevlar/epoxy composites with various loading speeds was observed. Results indicate values of ILSS were increased at higher cross head speeds as compared to ambient temperature. Fibrillation progression and matrix failure (riverline marking) was observed by SEM. A change in cross head speed may result in variation of failure modes.