89 / 2025-05-14 21:51:48

Nonlinear Fatigue Reliability Analysis Based on A Modified Toughness Exhaustion Damage Approach

nonlinear fatigue danage,PDEM,Time-dependent reliability analysis,Fatigue life prediction,Dual-parameter modeling

To address the nonlinear and stochastic characteristics of fatigue damage evolution under variable amplitude loading, a nonlinear fatigue damage accumulation model incorporating toughness and residual strength as dual parameters is proposed. A time-dependent reliability analysis framework is further established based on the probability density evolution method. By introducing random variables to characterize the scatter in fatigue life and employing numerical solutions to capture the probability density evolution, the proposed method systematically reflects the uncertainty propagation during fatigue damage processes. Fatigue experiments and reliability analyses conducted on 300M steel, 41Cr4 steel, and 16Mn steel demonstrate that the proposed model outperforms existing approaches in terms of prediction accuracy and reliability assessment stability. This study provides a novel theoretical basis for fatigue life evaluation and reliability design of engineering structures, with promising engineering application potential.