scholarly journals A microstructure sensitive modeling approach for fatigue life prediction considering the residual stress effect from heat treatment

2018 ◽  
Vol 13 ◽  
pp. 2048-2052 ◽  
Author(s):  
Chao Gu ◽  
Junhe Lian ◽  
Yanping Bao ◽  
Sebastian Münstermann
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Stress Effect ◽  
Modeling Approach ◽  
Residual Stress Effect

Fatigue‐life prediction of additively manufactured material: Effects of heat treatment and build orientation

2020 ◽  
Vol 43 (4) ◽  
pp. 831-844 ◽  
Author(s):  
Aref Yadollahi ◽  
Mohamad Mahmoudi ◽  
Alaa Elwany ◽  
Haley Doude ◽  
Linkan Bian ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Build Orientation

The Ability of Current Models for Fatigue Life Prediction of Shot Peened Components

2009 ◽  
Vol 417-418 ◽  
pp. 901-904 ◽  
Author(s):  
Ricardo A. Cláudio ◽  
José M. Silva ◽  
Carlos M. Branco ◽  
Jim Byrne
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Fracture Mechanics ◽  
Shot Peening ◽  
Life Prediction ◽  
Compressive Residual Stress ◽  
Prediction Models ◽  
Critical Distance ◽  
Fatigue Life Prediction ◽  
Distance Methods

It is well known that shot peening has a marked benefit on fatigue life for the majority of applications. This effect is attributed mainly due to the compressive residual stress state at the component’s surface due to shot peening. The present paper evaluates the ability of several fatigue life prediction models, commonly used for general analyses, to predict the behaviour of components with compressive residual stress due to shot peening. Advanced elastic-plastic finite element analyses were carried out in order to obtain stress, strain, strain energy and fracture mechanics parameters for cracks within a compressive residual stress field. With these results several total fatigue life prediction models (including critical distance methods) and fracture mechanics based models were applied in order to predict fatigue life. Fatigue life predictions were compared with several experimental fatigue tests carried out on specimens, representative of a critical region of a compressor disc in a gas turbine aero engine. The results obtained showed that total fatigue life methods, even if combined with critical distance methods, give conservative results when shot peening is considered. Fatigue life was successfully predicted using the method proposed by Cameron and Smith, by adding initiation life to crack propagation life. This last method was also successfully applied for the prediction of non-propagating cracks that were observed during the experimental tests.

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.

Fatigue Life Prediction of an Autofrettaged Thick-Walled Pressure Vessel With an External Groove

1991 ◽  
Vol 113 (3) ◽  
pp. 368-374 ◽  
Author(s):  
S. K. Koh ◽  
R. I. Stephens
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Stress Concentration ◽  
Pressure Vessel ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Fatigue Life Prediction ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Operating Stress

An autofrettaged thick-walled pressure vessel with an external groove subjected to a pulsating internal pressure can have fatigue failures at the external groove root due to the combination of tensile autofrettage residual stress, operating stress, and stress concentration. To predict the fatigue life of the autofrettaged thick-walled pressure vessel with an external groove, the local strain approach was applied. The residual stress distribution due to autofrettage and the operating stress distribution due to internal pressure were determined using finite element analysis which resulted in theoretical stress concentration factors. To account for the mean stress effects on the fatigue life prediction of the pressure vessel, low-cycle fatigue behavior with several strain ratios was obtained using smooth axial specimens taken from the ASTM A723 thick-walled steel pressure vessel. Fatigue life predictions were made by incorporating the local strains determined from the linear rule and Neuber’s rule and the Morrow and SWT mean stress parameters determined from low-cycle fatigue tests. The predicted fatigue lives were within factors of 2 to 4, compared to simulated experimental fatigue lives based upon fatigue cracks of 2.5 mm in length. These procedures appear to be realistic for evaluating fatigue lives for this complex pressure vessel.

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