A nonlinear fatigue damage accumulation model considering strength degradation and its applications to fatigue reliability analysis

Abstract

Fatigue is a damage accumulation process in which the material property deteriorates and degenerates continuously under cyclic loading. The analysis of damage accumulation plays a key role in preventing the occurrence of fatigue failures, and the damage evolution mechanism is one of the important focuses of fatigue behavior. In this paper, a residual strength degradation model according to the stress-strength interference (SSI) model is introduced firstly; then a modified nonlinear fatigue damage accumulation model based on the Manson-Halford theory is proposed. Combining the proposed nonlinear damage accumulation model with the residual strength degradation model, a new method is developed for fatigue life prediction under constant and variable amplitude loading, which considers not only the effects of load interactions, but also the phenomenon of strength degradation of materials induced by loading history, and it can be used to predict the reliability and fatigue life of mechanical components. Moreover, the material parameter for the residual strength degradation can be obtained directly from S-N curve without running extra experiments. Finally, experimental data are used to compare with the predicted value in order to demonstrate the proposed residual strength degradation model. In addition, two sets of experimental data are also used to verify the proposed nonlinear fatigue damage accumulation model which is applied to predict fatigue life under two-stress level loading and reliability prediction under multi-stress level loading. The results show that the proposed method has a good agreement between the experimental data and predicted values.

A Review on Fatigue Life Prediction Methods for Metals

“…Hashin and Rotem [151], Ben-Amoz [152], Subramanyan [153], and Leipholz [154] proposed in the past a variety of life curve modification theories; also various nonlinear cumulative damage fatigue life prediction methods can be found in literature [155][156][157][158].…”

A fatigue driving energy approach to high‐cycle fatigue life estimation under variable amplitude loading

“…Simultaneously, the bigger difference between the applied stress levels, the greater effect it shows. This phenomenon (load interactions) is commonly described in a manner of load ratio (interaction factor), reported by Corten and Dolan, 39 Freudenthal and Heller, 34 Morrow 35 and Huang et al 19,38,40 As aforementioned, considering a two-level loading (n 1 cycles at σ 1 followed by n 2 cycles at σ 2 to failure), the phase of damage evolution at the first stress σ 1 remains the same as its original evolution law under CAL, while the phase at the second stress σ 2 will change. In this study, assuming that the load ratio between two successive stress levels is used as an interaction factor to present load interactions.…”

Structural reliability analysis and uncertainties‐based collaborative design and optimization of turbine blades using surrogate model

“…[46][47][48][49][50][51][52] This process can affect the reliability of equipment performance or even result in the failure of works. 12,[53][54][55][56][57][58][59][60][61] To enhance safety, many different uncertainty analysis and reliability evaluation approaches were proposed and developed in the past decades. In general, three types of these approaches are usually been utilized.…”