Multiaxial fatigue reliability assessment using a differential ant-stigmergy algorithm

This study presents a process of establishing a multiaxial Weibull model to assess S45C steel reliability and high-cycle fatigue. The proposed model includes multiaxial stress state, stress gradient and component size factors, and the probability of failure. The model was based on multiaxial fatigue theory, where the expressed damage parameter is a single value for one cycle of the multiaxial stress state, combined with the weakest link concept. Through the maximum likelihood method (MLE), a probabilistic stress-life (P-S-N) curve that reflects both failure and right-censored data was plotted; whereas optimal Weibull parameters were estimated via the differential ant-stigmergy algorithm (DASA). The completed multiaxial Weibull model was then applied to S45C steel tensioncompression (TC) and zero-tension (ZT) fatigue test data, both of which agreed well. Afterward, the model was cross-checked with torsion fatigue test data results for validity.