Stochastic fatigue analysis of glass fiber reinforced polymer pipes

Abstract

The fatigue lifetime of composite pipe subjected to cyclic internal hydrostatic pressure with variable amplitudes is considered. Progressive damage modeling technique is utilized on the basis of stiffness degradation for monitoring damage progress in composite structure. The modeling which consists of three different phases as stress analysis, damage estimation and mechanical properties degradation is implemented in parallel with the random generation of fatigue loading pattern. All involved parameters defining the fatigue loading scheme, including maximum stress amplitude, mean stress amplitude and number of cycles are treated as random variables resembling real conditions of pipes in the operational field. Therefore, instead of deterministic fatigue analysis as a normal practice regulated by normative standards for the experimental analysis, full stochastic fatigue modeling is conducted. Obtained results are statistically analyzed and the probability of each estimated fatigue lifetime is reported.