Numerical Modeling of Distributed Inhomogeneities and Their Effect on Rolling-Contact Fatigue Life

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Qinghua Zhou ◽  
Lechun Xie ◽  
Xiaoqing Jin ◽  
Zhanjiang Wang ◽  
Jiaxu Wang ◽  
...  
Keyword(s):  
Numerical Solution ◽  
Life Prediction ◽  
Solution Method ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Inhomogeneous Materials ◽  
Equivalent Inclusion Method ◽  
Contact Fatigue Life ◽  
Influence Radius

The present work proposes a new efficient numerical solution method based on Eshelby's equivalent inclusion method (EIM) to study the influence of distributed inhomogeneities on the contact of inhomogeneous materials. Benchmark comparisons with the results obtained with an existing numerical method and the finite element method (FEM) demonstrate the accuracy and efficiency of the proposed solution method. An effective influence radius is defined to quantify the scope of influence for inhomogeneities, and the biconjugate gradient stabilized method (Bi-CGSTAB) is introduced to determine the eigenstrains of a large number of inclusions efficiently. Integrated with a rolling-contact fatigue (RCF) life prediction model, the proposed numerical solution is applied to investigate the RCF life of (TiB + TiC)/Ti-6Al-4V composites, and the results are compared with those of a group of RCF tests, revealing that the presence of the reinforcements causes reduction in the RCF lives of the composites. The comparison illustrates the capability of the proposed solution method on RCF life prediction for inhomogeneous materials.

Numerical Simulation of Material Sub-Surface Defects in Rolling Contact Fatigue

2005 ◽  
Author(s):  
M. Taraf ◽  
M. F. Ghanameh ◽  
M. Mliha Touati ◽  
O. Oussouaddi ◽  
A. Zeghloul
Keyword(s):  
Numerical Simulation ◽  
Life Prediction ◽  
Surface Defects ◽  
Rolling Contact Fatigue ◽  
Fatigue Crack Initiation ◽  
Contact Fatigue ◽  
Multiaxial Fatigue ◽  
Rolling Contact ◽  
Contact Fatigue Life ◽  
Four Levels

To ensure the safety and of reducing the costs of maintenances in railways systems, it is necessary to evaluate the life prediction of fatigue crack initiation in rolling contact fatigue starting from the defects. The influence of defects on the rolling contact fatigue was studied, we simulated two types of geometry of defect (circular and elliptic) and also we studied the influence of defects clusters. The stresses and deformations were analyzed in the vicinity of the defect. Calculations were carried out with four levels of loading with the code of finite elements ABAQUS-standard (version 6.3). The fatigue impact was evaluated by using the multiaxial fatigue parameter to estimate the rolling contact fatigue life.

Numerical Modeling of Distributed Inhomogeneities and Their Effect on Rolling Contact Fatigue Life

2012 ◽  
Author(s):  
Qinghua Zhou ◽  
Xiaoqing Jin ◽  
Zhanjiang Wang ◽  
Jiaxu Wang ◽  
Leon M. Keer ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Hertzian Contact ◽  
Principle Of Superposition ◽  
Equivalent Inclusion Method ◽  
Life Model ◽  
Solution Methods ◽  
Contact Fatigue Life

This research explores the influence of distributed non-overlapping inhomogeneities on the contact properties of a material. Considered here is the half-space Hertzian contact of a sphere with an inhomogeneous material. The numerical analysis is conducted utilizing a simplified model based on Eshelby’s Equivalent Inclusion Method (EIM) and the principle of superposition. The solutions take into account interactions between all inhomogeneities. Benchmark comparisons with the results obtained with the finite element method (FEM) demonstrate the accuracy and efficiency of the proposed solution methods. The emphasis is given to a parametric study of the effect of inhomogeneities in a Gaussian distribution on material properties. Both compliant and stiff inhomogeneities are modeled. Material inhomogeneities strongly affect rolling contact fatigue (RCF) of a material, and a modified RCF life model is suggested. Homogenization and extensive numerical simulations result in semi-empirical fatigue-life reduction parameters to characterize the influence of material inhomogeneities.

Effect of Grain Flow Orientation on Rolling Contact Fatigue Life of AISI M-50

1982 ◽  
Vol 104 (3) ◽  
pp. 330-334 ◽  
Author(s):  
A. H. Nahm
Keyword(s):  
Fatigue Life ◽  
Flow Line ◽  
Flow Direction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Vacuum Arc ◽  
Type I ◽  
Grain Flow ◽  
Contact Fatigue Life

Accelerated rolling contact fatigue tests were conducted to study the effect of grain flow orientation on the rolling contact fatigue life of vacuum induction melted and vacuum arc remelted (VIM-VAR) AISI M-50. Cylindrical test bars were prepared from a billet with 0, 45, and 90 deg orientations relative to billet forging flow direction. Tests were run at a Hertzian stress of 4,826 MPa with a rolling speed of 12,500 rpm at room temperature, and lubricated with Type I (MIL-L-7808G) oil. It was observed that rolling contact fatigue life increased when grain flow line direction became more parallel to the rolling contact surface.

Influence of ZnDTP on Rolling Contact Fatigue Life under Grease Lubrication

2021 ◽  
Vol 2021.59 (0) ◽  
pp. 05a5
Author(s):  
Hirotomo HOSOI ◽  
Yugo KAMEI ◽  
Hirotoshi AKIYAMA ◽  
Jusei MAEDA ◽  
Masanori SEKI
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Grease Lubrication ◽  
Contact Fatigue Life

Evaluation of contact fatigue life of a wind turbine carburized gear considering gradients of mechanical properties

2018 ◽  
Vol 28 (8) ◽  
pp. 1170-1190 ◽  
Author(s):  
Wei Wang ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Zhangdong Sun
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Heavy Duty ◽  
Initial Residual Stress ◽  
Contact Fatigue Life ◽  
Carburized Gear ◽  
Load Conditions

Case hardening processes such as carburizing are extensively applied in heavy-duty gears used in wind turbines, ships, high-speed rails, etc. Contact fatigue failure occurs commonly in engineering practice, thus reduces reliabilities of those machines. Rolling contact fatigue life of a carburized gear is influenced by factors such as the gradients of mechanical properties and profile of initial residual stress. In this regard, the study of contact fatigue life of carburized gears should be conducted with the consideration of those aspects. In this study, a finite element elastic–plastic contact model of a carburized gear is developed which takes the gradients of hardness and initial residual stress into account. Initial residual stress distribution and the hardness profile along the depth are obtained through experimental measurements. The effect of the hardness gradient is reflected by the gradients of yield strength and fatigue parameters. The modified Fatemi–Socie strain-life criterion is used to estimate the rolling contact fatigue life of the heavy-duty carburized gear. Numerical results reveal that according to the Fatemi–Socie fatigue life criterion, rolling contact fatigue failure of the carburized gear will first initiate at subsurface rather than surface. Compared with the un-carburized gear, the rolling contact fatigue lives of the carburized gear under all load conditions are significantly improved. Under heavy load conditions, the carburized layer significantly reduces the fatigue damage mainly due to the benefit to inhibit the accumulation of plasticity. Influence of the residual stress is also investigated. Under the nominal load condition, compared with the residual stress-free case, the existence of the tensile residual stress causes remarkable deterioration of the rolling contact fatigue life while the compressive residual stress with the same magnitude leads to a moderate growth of the rolling contact fatigue life. As the load becomes heavier when plasticity becomes notable, the influence of the initial residual stress on the life is somewhat weakened.

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