Nonlinear Fatigue Damage Accumulation Under Random Loading

The analytical expressions for the probability densities of the cumulative fatigue damage and fatigue life and for the reliability function are obtained for a mechanical or structural component subject to stationary random stress process on the basis of a stochastic theory of fatigue damage accumulation proposed by the first author and his co-worker and the Morrow’s nonlinear damage rule. The comparison between the results from Morrow’s and Palmgren-Miner’s damage rules for the case when the stress is a narrow-band stationary Gaussian process with zero mean is made and some important conclusions are drawn.

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Different Fatigue Dynamics Under Statistically and Spectrally Similar Deterministic and Stochastic Excitations

Journal of Applied Mechanics ◽

10.1115/1.4025138 ◽

2013 ◽

Vol 81 (4) ◽

Cited By ~ 4

Author(s):

Son Hai Nguyen ◽

Mike Falco ◽

Ming Liu ◽

David Chelidze

Keyword(s):

Crack Growth ◽

Fatigue Damage ◽

Damage Accumulation ◽

Growth Dynamics ◽

Experimental System ◽

Counting Method ◽

Random Loading ◽

Stochastic Excitations ◽

Fatigue Damage Accumulation ◽

System Coupling

Estimating and tracking crack growth dynamics is essential for fatigue failure prediction. A new experimental system—coupling structural and crack growth dynamics—was used to show fatigue damage accumulation is different under chaotic (i.e., deterministic) and stochastic (i.e., random) loading, even when both excitations possess the same spectral and statistical signatures. Furthermore, the conventional rain-flow counting method considerably overestimates damage in case of chaotic forcing. Important nonlinear loading characteristics, which can explain the observed discrepancies, are identified and suggested to be included as loading parameters in new macroscopic fatigue models.

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Fatigue Damage Accumulation Under Quasi-Random Loading of Composite Airframe Elements

Mechanics of Composite Materials ◽

10.1007/s11029-016-9597-9 ◽

2016 ◽

Vol 52 (4) ◽

pp. 455-468 ◽

Cited By ~ 3

Author(s):

V. Strizhius

Keyword(s):

Fatigue Damage ◽

Damage Accumulation ◽

Random Loading ◽

Fatigue Damage Accumulation

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Cumulative fatigue damage assessment and life predictions of as-forged vs QT V-based MA steels using two-step loading experiments

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/146442070321700206 ◽

2003 ◽

Vol 217 (2) ◽

pp. 145-155 ◽

Cited By ~ 1

Author(s):

L Yang ◽

A Fatemi

Keyword(s):

Fatigue Damage ◽

Life Prediction ◽

Damage Accumulation ◽

Damage Models ◽

Fatigue Damage Accumulation ◽

Loading Tests ◽

Cumulative Fatigue Damage ◽

Life Predictions ◽

Different Characteristics ◽

Quenching And Tempering

This study examines the fatigue damage accumulation process associated with a commonly produced forged vanadium-based microalloyed (MA) steel and its comparison with its quenched and tempered (Q&T) counterpart at the same hardness level. The advantage of MA steels compared to the traditional Q&T steels is the elimination of the costly quenching and tempering processes. Completely reversed strain-controlled two-level block loading tests were conducted on smooth axial specimens at room temperature. Under multi-level block cycling, the two steels displayed different characteristics, though they showed similar behaviour in constant amplitude fatigue. Therefore, a key to successful assessment of fatigue damage accumulation under variable amplitude service loading is selection of an appropriate cumulative fatigue life prediction model which reflects the material's damage characteristics. The effectiveness of several cumulative fatigue damage models and their life prediction capabilities are evaluated using the experimental data.

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Probabilistic Modeling of Fatigue Damage Accumulation for Reliability Prediction

International Journal of Quality Statistics and Reliability ◽

10.1155/2011/718901 ◽

2011 ◽

Vol 2011 ◽

pp. 1-10 ◽

Cited By ~ 32

Author(s):

Vijay Rathod ◽

Om Prakash Yadav ◽

Ajay Rathore ◽

Rakesh Jain

Keyword(s):

Fatigue Damage ◽

Stress Level ◽

Damage Accumulation ◽

Probabilistic Modeling ◽

Nonstationary Process ◽

Reliability Prediction ◽

Fatigue Damage Accumulation ◽

Cumulative Fatigue Damage ◽

Single Stress ◽

Level Loading

A methodology for probabilistic modeling of fatigue damage accumulation for single stress level and multistress level loading is proposed in this paper. The methodology uses linear damage accumulation model of Palmgren-Miner, a probabilistic S-N curve, and an approach for a one-to-one transformation of probability density functions to achieve the objective. The damage accumulation is modeled as a nonstationary process as both the expected damage accumulation and its variability change with time. The proposed methodology is then used for reliability prediction under single stress level and multistress level loading, utilizing dynamic statistical model of cumulative fatigue damage. The reliability prediction under both types of loading is demonstrated with examples.

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

Volume 10: ASME 2015 Power Transmission and Gearing Conference; 23rd Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2015-46953 ◽

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.

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