A weight function-critical plane approach for low-cycle fatigue under variable amplitude multiaxial loading

2006 ◽  
Vol 29 (4) ◽  
pp. 331-339 ◽  
Author(s):  
X. CHEN ◽  
D. JIN ◽  
K. S. KIM
Keyword(s):  
Weight Function ◽  
Low Cycle Fatigue ◽  
Multiaxial Loading ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Variable Amplitude ◽  
Critical Plane Approach

A weight function method for multiaxial low-cycle fatigue life prediction under variable amplitude loading

2018 ◽  
Vol 53 (4) ◽  
pp. 197-209 ◽  
Author(s):  
Xiao-Wei Wang ◽  
De-Guang Shang ◽  
Yu-Juan Sun
Keyword(s):  
Fatigue Life ◽  
Weight Function ◽  
Life Prediction ◽  
Function Method ◽  
Low Cycle Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Variable Amplitude ◽  
Weight Function Method

A weight function method based on strain parameters is proposed to determine the critical plane in low-cycle fatigue region under both constant and variable amplitude tension–torsion loadings. The critical plane is defined by the weighted mean maximum absolute shear strain plane. Combined with the critical plane determined by the proposed method, strain-based fatigue life prediction models and Wang-Brown’s multiaxial cycle counting method are employed to predict the fatigue life. The experimental critical plane orientation and fatigue life data under constant and variable amplitude tension–torsion loadings are used to verify the proposed method. The results show that the proposed method is appropriate to determine the critical plane under both constant and variable amplitude loadings.

Multi-Axial Fatigue Life Model Evaluation and Life Prediction for Turbine Disk

2011 ◽  
Vol 130-134 ◽  
pp. 2330-2334
Author(s):  
Jun Hong Zhang ◽  
Feng Lv ◽  
Wen Peng Ma
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Turbine Disk ◽  
Strain History ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Element Analysis ◽  
Critical Plane Approach ◽  
Axial Fatigue

Multi-axial low cycle fatigue was the main failure mode of turbine disk. Critical plane approach was an idea method for the prediction of multi-axial fatigue life. A lot of models based on critical plane approach have been put forward, but there is not a universal prediction model. In order to find a model for turbine disk, linear heteroscedastic regression analysis of the standard low cycle fatigue data was carried out to obtained fatigue parameters. After verifying the accuracy of the finite element model, the stress and strain history of the danger point was obtained based on elastic-plastic finite element analysis. The critical plane and the damage of it was found by the method of coordinate transformation. The fatigue life of turbine disk was estimated by different models, and the results were quite different. SWT-Bannantine model was more suitable for the turbine disk.

Low-Cycle Fatigue Life Prediction by a New Critical-Plane Method

2008 ◽  
Vol 385-387 ◽  
pp. 209-212
Author(s):  
Dan Jin ◽  
Jian Hua Wu ◽  
Yang Zhang
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Weight Function ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Plane Method ◽  
Rainflow Cycle Counting

A series of low-cycle fatigue experiments of axial-torsional loading of variable amplitudes were performed on the tubular specimens of 304 stainless steel. Two models of multiaxial low-cycle fatigue life, KBM and FS method, are evaluated based on the fatigue life data of 304 stainless steel. Rainflow cycle counting and the Liner Damage Rule are used to calculate fatigue damage. It was shown that the part prediction results are nonconservative for the two models. The life prediction is done again based on the weight function critical plane method for the two models. The prediction results are better by using the weight function critical plane method than the previous results for KBM model. But the prediction results are improved little for FS model in spite of the weight function critical plane method being used.

Low-Cycle Fatigue Performance of Buckling Restrained Braces and Assessment of Cumulative Damage under Severe Earthquakes

2018 ◽  
Vol 763 ◽  
pp. 867-874
Author(s):  
Yu Shu Liu ◽  
Ke Peng Chen ◽  
Guo Qiang Li ◽  
Fei Fei Sun
Keyword(s):  
Fatigue Life ◽  
Energy Dissipation ◽  
Structural Reliability ◽  
Low Cycle Fatigue ◽  
Engineering Application ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Variable Amplitude ◽  
Buckling Restrained Braces ◽  
Energy Dissipation Devices

Buckling Restrained Braces (BRBs) are effective energy dissipation devices. The key advantages of BRB are its comparable tensile and compressive behavior and stable energy dissipation capacity. In this paper, low-cycle fatigue performance of domestic BRBs is obtained based on collected experimental data under constant and variable amplitude loadings. The results show that the relationship between fatigue life and strain amplitude satisfies the Mason-Coffin equation. By adopting theory of structural reliability, this paper presents several allowable fatigue life curves with different confidential levels. Besides, Palmgren-Miner method was used for calculating BRB cumulative damages. An allowable damage factor with 95% confidential level is put forward for assessing damage under variable amplitude fatigue. In addition, this paper presents an empirical criterion with rain flow algorithm, which may be used to predict the fracture of BRBs under severe earthquakes and provide theory and method for their engineering application. Finally, the conclusions of the paper were vilified through precise yet conservative prediction of the fatigue failure of BRB.

An Experimental Evaluation for Four Multiaxial Fatigue Approaches

2014 ◽  
Vol 627 ◽  
pp. 425-428
Author(s):  
Dan Jin ◽  
Da Jiang Tian ◽  
Qi Zhou Wu ◽  
Wei Lin
Keyword(s):  
Low Cycle Fatigue ◽  
Multiaxial Fatigue ◽  
304 Stainless Steel ◽  
Normal Strain ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Maximum Shear Strain ◽  
Rainflow Cycle Counting ◽  
Tubular Specimens ◽  
Damage Rule

A series of tests for low cycle fatigue were conducted on the tubular specimens for 304 stainless steel under variable amplitude and irregular axial-torsional loading. Rainflow cycle counting and linear damage rule are used to calculate fatigue damage and four approaches, e.g. SWT(Smith-Watson-Topper), KBM(Kandil-Brown-Miller), FS(Fatemi-Socie), and LKN(Lee-Kim-Nam) approach are employed to predict the fatigue life. The maximum shear strain plane, the maximum normal strain plane, and the maximum damage plane are considered as the critical plane, respectively. The effects of the choice of the critical plane on previous approaches are discussed. It is shown that comparing with the maximum shear/normal strain approach, the predictions are improved by using the maximum damage plane approach, part nonproportional paths for SWT, AV and part nonproportional paths for KBM, TV paths for FS. But for LKN, the prediction results are nonconservative for some paths than that of the maximum shear/normal strain approach.

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