Study on effect of mean stress on fatigue life prediction of thin film structure

2016 ◽  
Vol 30 (4) ◽  
pp. 1547-1554 ◽  
Author(s):  
Myung-Soo Shin ◽  
Jun-Hyub Park ◽  
Jung Yup Kim
Keyword(s):  
Thin Film ◽  
Fatigue Life ◽  
Life Prediction ◽  
Film Structure ◽  
Fatigue Life Prediction ◽  
Mean Stress ◽  
Thin Film Structure

Fatigue-life prediction under irregular stress conditions

1970 ◽  
Vol 5 (3) ◽  
pp. 207-211 ◽  
Author(s):  
T H Erismann
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Stress Conditions ◽  
Fatigue Life Prediction ◽  
Mean Stress ◽  
Arbitrary Loading ◽  
Empirical Determination ◽  
The Mean ◽  
Standard Tests

The present work is a shorter version of a more detailed treatise by the author (1)∗. The method consists of two parts: the empirical determination of certain characteristics of a material by means of a relatively small number of well defined standard tests, and the arithmetical application of the results obtained to arbitrary loading histories. The following groups of parameters are thus taken into account: the variations of the mean stress; the interaction of these variations and the superposed oscillating stresses; the spectrum of the oscillating-stress amplitudes; the sequence of the oscillating-stress amplitudes.

FATIGUE LIFE PREDICTION OF ROLLED AZ31 MAGNESIUM ALLOY USING AN ENERGY-BASED MODEL

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5503-5508 ◽  
Author(s):  
SUNG HYUK PARK ◽  
SEONG-GU HONG ◽  
BYOUNG HO LEE ◽  
CHONG SOO LEE
Keyword(s):  
Fatigue Life ◽  
Magnesium Alloy ◽  
Deformation Behavior ◽  
Strain Energy ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Az31 Magnesium Alloy ◽  
Stress And Strain ◽  
Mean Stress ◽  
The Mean

Fatigue behavior of rolled AZ31 magnesium alloy, which shows an anisotropic deformation behavior due to the direction dependent formation of deformation twins, was investigated by carrying out stress and strain controlled fatigue tests. The anisotropy in deformation behavior introduced asymmetric stress-strain hysteresis hoops, which make it difficult to use common fatigue life prediction models, such as stress and strain-based models, and induced mean stress and/or strain even under fully-reversed conditions; the tensile mean stress and strain were found to have a harmful effect on the fatigue resistance. An energy-based model was used to describe the fatigue life behavior as strain energy density was stabilized at the early stage of fatigue life and nearly invariant through entire life. To account for the mean stress and strain effects, an elastic energy related to the mean stress and a plastic strain energy consumed by the mean strain were appropriately considered in the model. The results showed that there is good agreement between the prediction and the experimental data.

scholarly journals Fatigue Life Prediction of Rolling Bearings Based on Modified SWT Mean Stress Correction

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Aodi Yu ◽  
Hong-Zhong Huang ◽  
Yan-Feng Li ◽  
He Li ◽  
Ying Zeng
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Sensitivity Coefficient ◽  
Fatigue Life Prediction ◽  
Stress Effect ◽  
Mean Stress ◽  
Rolling Bearings ◽  
Contact Loads ◽  
Compensation Factor ◽  
The Mean

AbstractThe existing engineering empirical life analysis models are not capable of considering the constitutive behavior of materials under contact loads; as a consequence, these methods may not be accurate to predict fatigue lives of rolling bearings. In addition, the contact stress of bearing in operation is cyclically pulsating, it also means that the bearing undergo non-symmetrical fatigue loadings. Since the mean stress has great effects on fatigue life, in this work, a novel fatigue life prediction model based on the modified SWT mean stress correction is proposed as a basis of which to estimate the fatigue life of rolling bearings, in which, takes sensitivity of materials and mean stress into account. A compensation factor is introduced to overcome the inaccurate predictions resulted from the Smith, Watson, and Topper (SWT) model that considers the mean stress effect and sensitivity while assuming the sensitivity coefficient of all materials to be 0.5. Moreover, the validation of the model is finalized by several practical experimental data and the comparison to the conventional SWT model. The results show the better performance of the proposed model, especially in the accuracy than the existing SWT model. This research will shed light on a new direction for predicting the fatigue life of rolling bearings.

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