Probabilistic Modeling of Fatigue Damage Accumulation under Spectrum Loading

2014 ◽  
Vol 684 ◽  
pp. 169-175
Author(s):  
Xian Min Chen ◽  
Hong Na Dui
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Engineering Application ◽  
Al Alloy ◽  
Numerical Verification ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Fatigue Damage Accumulation ◽  
Spectrum Loading

A probabilistic methodology for modeling fatigue damage accumulation and fatigue life under variable amplitude loading is proposed in this paper. With probabilistic modifications, the calculative consistency between fatigue damage and life is achieved in the model and the load sequence effects are properly accounted for variable amplitude loading. This damage model overcomes the inherent deficiencies in the linear damage accumulation rule but still preserves its simplicity for engineering application. With Monte Carlo sampling method, numerical verification of this model is conducted under two-level spectrum loading. The predicted probabilistic distributions of fatigue life are validated by the fatigue tests on Al-alloy straight lugs.

A Modified Model for Non-Linear Fatigue Damage Accumulation With Load Interaction Effects

2015 ◽  
Author(s):  
Zhaochun Peng ◽  
Hong-Zhong Huang ◽  
Huiying Gao ◽  
Zhiqiang Lv ◽  
Shun-Peng Zhu
Keyword(s):  
Experimental Data ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Interaction Effects ◽  
Variable Amplitude Loading ◽  
Modified Model ◽  
Variable Amplitude ◽  
Fatigue Damage Accumulation ◽  
Non Linear ◽  
Damage Rule

In the case of variable amplitude loading, fatigue damage accumulation theory is closely related to loading histories, such as load sequences, load interactions, and so on. Due to the lack of load histories, there may be a large deviation with the reality for linear damage rule (Miner rule). Although many non-linear fatigue damage accumulation models can deal with the effect of load sequences, load interaction effect cannot be ignored and it plays an important role in damage accumulation behavior. This paper describes the damage evolution behavior based on nonlinear damage rule under variable amplitude loading. A new method to describe the load interaction effects is proposed, it is assumed that the load ratio between adjacent stress levels is used to present this phenomenon. Thereafter, the method is introduced to a non-linear damage model, and a modified model is developed to predict the residual lifetime. Four categories of experimental data sets from literatures are employed to investigate the validity of the proposed model. The results indicate that the modified model shows a good agreement between experimental data and theoretical results. It is also found that the modified model demonstrates an improvement in prediction accuracy over the primary model and Miner rule. Furthermore, the modified model can be easily implemented with the use of Wöhler curve only.

scholarly journals Prediction of fatigue damage accumulation of defective materials under variable amplitude loading

2019 ◽  
Vol 234 (1) ◽  
pp. 65-75
Author(s):  
Maroua Saggar ◽  
Anouar Nasr ◽  
Haifa Sallem ◽  
Chokri Bouraoui
Keyword(s):  
Damage Accumulation ◽  
Surface Defect ◽  
Multiaxial Fatigue ◽  
Cumulative Damage ◽  
Strong Nonlinearity ◽  
Variable Amplitude Loading ◽  
Variable Amplitude ◽  
Fatigue Damage Accumulation ◽  
Artificial Surface ◽  
Free Material

The main goal of this attempt is to explore and analyze the behavior of a material containing artificial surface defect and solicited under variable amplitude cyclic loading. The observation and the follow-up of the loading history and the characterization of the damage accumulation were evaluated in the presence of an artificial surface defect. The results made it possible to highlight a strong nonlinearity of the damage accumulation. However, the absence of sequence effects encountered in a defect-free material has been found. In the perspective of developing an approach to evaluate the influence of the defects on cumulative damage under variable amplitude loading, this work consists of coupling a multiaxial fatigue criterion adapted to defective materials with a law of uniaxial damage solicited under variable amplitudes loading. A cumulative damage law has been used to analyze the validity of the proposed method. Introducing the equivalent multiaxial fatigue stress due to the presence of the defect allowed us to predict the residual lifetime of a defective material, and to find the effects of sequences usually observed for variable amplitude loading for the defect-free material. A coherent agreement is observed between the results predicted by the improved model and those obtained from the experimental investigations on specimens containing artificial surface defect subjected to purely alternating tension and torsion under increasing and decreasing load levels.

Fatigue damage accumulation around notches

2004 ◽  
Vol 46 (6) ◽  
pp. 309-313
Author(s):  
Yutaka Iino ◽  
Hideo Yano
Keyword(s):  
Fatigue Damage ◽  
Damage Accumulation ◽  
Fatigue Damage Accumulation
Sign in / Sign up

Export Citation Format

Share Document