The fatigue behaviour of filament-wound fiberglass/epoxy tubes under cyclic pressure

An experimental study of the behaviour of multidirectional filament-wound fiberglass/epoxy tubes under cyclic loading is presented. Commercially wound tubes were investigated under a biaxial loading condition. Two series of tests were conducted with the different pressure ratios, R = p(min)/p(max) = 0.05 and R = 0.3. The results are discussed based on macroscopic and microscopic damage observed. The hysteresis loops are analyzed and fatigue life curves are constructed. The fatigue results for the two R-ratios are reduced into a single life curve with a narrow scatter band, by using an effective stress damage parameter.