Effects of Residual Stress and Traction Force on the Contact Fatigue Life of Railway Wheels

2006 ◽  
Vol 326-328 ◽  
pp. 1067-1070
Author(s):  
Jung Won Seo ◽  
Hyun Mu Hur ◽  
Sung Tae Kwon ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Contact Fatigue ◽  
Traction Force ◽  
Railway Wheel ◽  
Traction Coefficient ◽  
Contact Fatigue Life ◽  
Railway Wheels ◽  
Effect Of Surface ◽  
Surface Removal

Damage often occurs on the surface of railway wheels due to wheel-rail contact fatigue. Since the wheel failure can cause derailment causing the loss of life and property, it should be removed prior to the wheel failure. The effect of surface removal on contact fatigue life has been investigated by many researchers, however, the effects of residual stress and traction force have not been reported yet. The railway wheel reserves the initial residual stress due to the manufacturing process, and this residual stress is changed by the thermal stress induced by braking. Also, the traction force is usually applied along with residual stress on wheels of locomotive and electric motor vehicle. In this study, the effect of surface removal on the contact fatigue life for a railway wheel has been evaluated by applying the rolling contact fatigue test. Also, the effect of traction force and change of residual stress on the contact fatigue life has been estimated by applying finite element analysis. It is found that the residual stress is a dominant factor determining the surface removal depth as far as the traction coefficient is less than 0.15. If the traction coefficient is greater than 0.2, however, the surface removal depth is observed to be independent on the residual stress.

The Effects of Residual Stress of Contact Fatigue Life for Railway Wheels

2005 ◽  
Vol 297-300 ◽  
pp. 115-121 ◽  
Author(s):  
Jung Won Seo ◽  
Byeong Choon Goo ◽  
Heung Chai Chung ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Life ◽  
Contact Fatigue ◽  
Contact Load ◽  
Evaluation Procedure ◽  
Railway Wheel ◽  
Railway Vehicles ◽  
Contact Fatigue Life ◽  
Railway Wheels

Railway wheels and axles belong to the most critical components in railway vehicles. The service conditions of railway vehicles became more severe in recent years due to the increase of speed. Therefore, a more precise evaluation of railway wheel life and safety has been requested. Wheel/rail contact fatigue and thermal cracks due to braking are two major mechanisms of the railway wheel failure. One of the main sources of the contact zone failure is the residual stress. The residual stress on wheel is formed during the manufacturing process which includes a heat treatment, and then, is changed in the process of braking which results in wheel/rail contact stress and thermal stress. In this paper, an evaluation procedure for the contact fatigue life of railway wheel including residual stress is proposed. Also, the cyclic stress history for fatigue analysis is simulated by applying finite element analysis for the moving contact load. As a result, a fatigue life estimation methodology is proposed for railway wheels which includes the effects of residual stresses due to heat treatment, braking and repeated contact load, respectively.

The Effects of Residual Stress of Contact Fatigue Life for Railway Wheels

2005 ◽  
pp. 115-121
Author(s):  
Jung Won Seo ◽  
Byeong Chun Goo ◽  
Heung Chai Chung ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Contact Fatigue ◽  
Contact Fatigue Life ◽  
Railway Wheels

The Contact Fatigue Life Evaluation According to Contact Surface Removal

2006 ◽  
Vol 321-323 ◽  
pp. 640-643
Author(s):  
Jung Won Seo ◽  
Seok Jin Kwon ◽  
Hyun Mu Hur ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Fatigue Life ◽  
Contact Surface ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Railway Vehicle ◽  
Element Analysis ◽  
Railway Wheel ◽  
Contact Fatigue Life ◽  
Surface Removal

Railway wheels and axles have been one of the most critical components in a railway vehicle. The service conditions of railway vehicles have became more severe in recent years due to the increase of the speed. It is very important to evaluate the reliability of wheels with regard to safety, because wheel failure can cause derailment with loss of life and property. One of the major reasons of the railway wheel damage is the contact zone failure by wheel/rail contact. One of the methods for preventing the failure and increasing the fatigue life is to grind periodically the contact surface before reaching the failure. The increase or decrease of the contact fatigue life by the surface removal of the contact surface were shown by many researchers. However, the reason why fatigue life increases or decrease has not been investigated obviously. In this study, the effect of the surface removal depth on the contact fatigue life for a railway wheel is evaluated through the employment of rolling contact fatigue tests and the finite element analysis. It is found that the contact fatigue life increased with the removal depth. But in the case that the removal depth is greater than the optimal depth, the contact fatigue life decreased. It seems to be obvious that the residual strain is the main factor determining the fatigue life according to the removal depth

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.

Finite Element Analysis of the Rolling Contact Fatigue Life of Railcar Wheels

2008 ◽  
Vol 575-578 ◽  
pp. 1461-1466
Author(s):  
Byeong Choon Goo ◽  
Jung Won Seo
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Element Analysis ◽  
Railway Vehicles ◽  
Contact Fatigue Life

Railcar wheels and axles belong to the most critical components in railway vehicles. The service conditions of railway vehicles have been more severe in recent years due to speed-up. Therefore, a more precise evaluation of railcar wheel life and safety has been requested. Wheel/rail contact fatigue and thermal cracks due to braking are two major mechanisms of the railcar wheel failure. One of the main sources influencing on the contact zone failure is residual stress. The residual stress in wheels formed during heat treatment in manufacturing changes in the process of braking. Thus the fatigue life of railcar wheels should be estimated by considering both thermal stress and rolling contact. Also, the effect of residual stress variation due to manufacturing process and braking process should be included in simulating contact fatigue behavior. In this paper, an evaluation procedure for the contact fatigue life of railcar wheels considering the effects of residual stresses due to heat treatment, braking and repeated contact load is proposed. And the cyclic stressstrain history for fatigue analysis is simulated by finite element analysis for the moving contact load.

Effect of Metal Removal and Initial Residual Stress on Contact Fatigue Life

2005 ◽  
Vol 29 (2) ◽  
pp. 341-349
Author(s):  
Hun-Mu Hur ◽  
Byeong-Choon Goo ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
Jung-Won Seo
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Metal Removal ◽  
Contact Fatigue ◽  
Initial Residual Stress ◽  
Contact Fatigue Life

Effect of Metal Removal and Traction Force on Contact Fatigue Life

2005 ◽  
Vol 29 (10) ◽  
pp. 1384-1391
Author(s):  
Jung-Won Seo ◽  
Hun-Mu Hur ◽  
Jae-Boong Choi ◽  
Young-Jin Kim
Keyword(s):  
Fatigue Life ◽  
Metal Removal ◽  
Contact Fatigue ◽  
Traction Force ◽  
Contact Fatigue Life
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