Stochastic fatigue limits and fatigue life variability in oriented-PVC pipe

Fatigue data has been collected on oriented polyvinyl chloride (PVC-O) pipe samples up to fatigue lifetimes of 107 cycles. A random fatigue limit model based on the work of Pascual and Meeker has been used to establish the fatigue limit in this material. This model assumes that the fatigue limit is a stochastic quantity and that the fatigue life is conditional on the fatigue limit. Moreover, it allows the use of censored data in establishing the fatigue limit magnitude. Although the most appropriate distributions for the fatigue life and the fatigue limit were difficult to determine unambiguously, the presence of a fatigue limit in PVC-O was established. This statistical analysis of the fatigue data allowed failure probability quantiles to be calculated for PVC-O pipe materials.