An assessment of mechanical behaviour and fractography study of glass/epoxy composites at different temperatures and loading speeds

Abstract

Effect of loading rate on fracture and mechanical behavior of autoclave cured glass fibre/epoxy prepreg composite has been studied at various loading (striking) rates (0.01-103mm/min). The maximum load carrying capacity and strain at yield continuously increases with increasing loading speed. The interlaminar shear strength (ILSS) value is high at low loading speed and becomes low at high loading speed with the transition of loading rate at approximately 300 mm/min. The formation of steps, welt interfacial failure and cleavage formation on matrix resin i.e. localized plastic deformation processes were dominating mechanisms for specimens tested at low loading rates, while brittle fracture of fibre, fibre pull-out and impregnation were dominating mechanisms for specimens tested at loading rates of 800 mm/min or higher.