Fatigue damage accumulation model of a High-Pressure oil pipe based on fatigue probability under Multi-Level cyclic loading

Abstract

Engineering components are often experienced variable amplitude cyclic loading during operation, making them susceptible to fatigue failure. Existing fatigue damage models are limited to laboratory research, with limited representation of key components of marine diesel engines. This study examines a Q345B high-pressure oil pipe (HOP). Based on a HOP fatigue life dispersion analysis and fatigue damage characterization, a fatigue damage accumulation model for multi-level cyclic loading and a method for calculating the remaining useful life are proposed. The proposed model considers fatigue life dispersion, loading sequence, and interaction effects. Experimental results verify the accuracy of the proposed model.