Progressive fatigue failure behavior of glass/epoxy (+/- 75)(2) filament-wound pipes under pure internal pressure

Fatigue failure behaviors of filament-wound composite pipes under pure internal pressure were investigated. The filament-wound pipes are made of E-glass/epoxy and have four layers which have +/-75 degrees winding angle. The fatigue tests have been done in accordance with ASTM D-2992, which stipulate 0.42 Hz frequency and R = 0.05 stress ratio. Tests have been performed at different load levels from 30% to 70% of ultimate tangential strength of the pipe, the damage progression such as whitening, leakage and final failure have been observed, and S-N curves of these damages were obtained. (C) 2009 Elsevier Ltd. All rights reserved.