Time-Dependent Reliability Analysis of Composite Repaired Pipes Subjected to Multiple Failure Modes

While metallic pipelines experience consistent deterioration due to aging, composite repair systems have become a method of interest over the recent decades. This study aims to deal with multiple failure modes of composite repaired pipes using probabilistic analysis. The failure modes—including bursting, adhesive debonding, and fracture—are all involved such that correlations among modes are considered to obtain the final system failure probability. The first passage probability method is applied to calculate the probability of failure in each failure mode. Additionally, the degradation process of the composite material is quantified by the Arrhenius relationship. It was found that adhesive debonding is the most influential failure mode, followed by bursting, then fracture due to internal pressure, and finally fracture induced by bending moment. The prominent input parameters were evaluated by carrying out a sensitivity analysis based on the FOSM reliability method. The results confirmed that composite repair parameters, including elasticity modulus, bonding strength, and thickness, noticeably impact the failure probability. The outcomes of this paper can help maintenance engineers better assess the reliability of composite repaired pipelines.