Multiaxial Fatigue Life Prediction of the CII Platform Leg Based on Critical Plane Energy Method

Abstract

Based on the critical plane energy method to build a plastic strain energy function on the critical plane, the approach of hot spot plastic strain energy as assessment parameters of fatigue damage is used and the shortcomings that the traditional energy method as a scalar is difficult to describe the direction of crack propagation is overcomed. By the rules of cracks expansion through critical plane, the fatigue life model parameters have a clear physical significance. W-S algorithm process is deduced, so the complex stress state is equivalent to a series of symmetric cyclic stress based on energy and structural damage caused by everyone is calculated. The research, fatigue life prediction of the key component on CII platform under random waves and flow loadings, has theoretical significance and value of engineering application.