The Strength of Surfaces in Rolling Contact

1989 ◽  
Vol 203 (3) ◽  
pp. 151-163 ◽  
Author(s):  
K L Johnson
Keyword(s):  
Plastic Deformation ◽  
Load Capacity ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Shear Cracks ◽  
Fatigue Wear ◽  
Modes Of Failure ◽  
Wheel Rolling ◽  
Traction Drives ◽  
Cyclic Plastic Deformation

The common engineering applications of rolling contact are reviewed: the wheel, rolling bearings, traction drives, gears and cams. It is shown that increasing the rigidity of the materials and decreasing the conformity of the surfaces reduces the resistance to rolling, but only at the expense of higher contact stress. The principal modes of failure are described: plastic deformation, contact fatigue, wear, scuffing and corrugation. Recent research into plastic deformation and fatigue is discussed. It is concluded that, if wear and scuffing are controlled by adequate lubrication and surface finish, and clean steel is used, the load capacity and life are governed by the nucleation of micro shear cracks through the action of cyclic plastic deformation.

Optimized Mapping of Pressure in Lubricated Point Contacts Based on Measured Film Thickness

2007 ◽  
Author(s):  
Radek Polisˇcˇuk ◽  
Michal Vaverka ◽  
Martin Vrbka ◽  
Ivan Krˇupka ◽  
Martin Hartl
Keyword(s):  
Film Thickness ◽  
Numerical Solution ◽  
Point Contact ◽  
Contact Fatigue ◽  
Lubricant Film ◽  
Rolling Contact ◽  
Experimental Film ◽  
Lubricated Contacts ◽  
Practical Performance ◽  
Traction Drives

The surface topography plays significant role in lifetime of highly loaded machine parts with lubricated contacts. Many elements like gears, rolling bearings, cams and traction drives operate in mixed lubrication conditions, where the lubricant film behavior closely implies the main practical performance parameters such as friction wear, contact fatigue and scuffing. For prediction of wear and especially contact fatigue, the values and distribution of the pressure in rolling contact are often required. The usual theoretical approach based on numerical solution of physical-mathematical models built around the Reynolds equation can be extremely time consuming, especially when lubricant films are very thin, and contact load and required resolution very high. This study presents a further refined approach to our previously published experimental method, based on on inverse elasticity theory and fast convolution transformation between the lubricant film thickness map and the pressure distribution within the point contact. The experimental film thickness maps of EHD lubricated contacts with smooth and dented surfaces were processed using colorimetric interferometry and validated using numerical solution, in order to calibrate numerical parameters and to find limits of the new approach.

scholarly journals Effect of Gas Nitriding on Interface Adhesion and Surface Damage of CL60 Railway Wheels under Rolling Contact Conditions

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 911
Author(s):  
Qiang Wu ◽  
Tao Qin ◽  
Mingxue Shen ◽  
Kangjie Rong ◽  
Guangyao Xiong ◽  
...  
Keyword(s):  
Wear Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wheel Surface ◽  
Fatigue Wear ◽  
Material Loss ◽  
Surface Protection ◽  
Gas Nitriding ◽  
Railway Wheels

The influence of surface gas nitriding on wheel/rail rolling contact fatigue and wear behavior of CL60 wheel was studied on a new rolling contact fatigue/wear tester (JD-DRCF/M). The failure mechanisms of the wheel/rail surface after the gas nitriding and without gas nitriding on the wheel surface were compared and analyzed. The results show that the wheel with gas nitriding could form a dense and hard white bright layer which was approximately 25 μm thick and a diffusion layer which was approximately 70 μm thick on the wheel surface. Thus, the gas nitriding on the railway wheel not only significantly improved the wear resistance on the surface of the wheel, but also effectively reduced the wear of the rail; the results show that the material loss reduced by 58.05% and 10.77%, respectively. After the wheel surface was subjected to gas nitriding, the adhesive coefficient between the wheel/rail was reduced by 11.7% in dry conditions, and was reduced by 18.4% in water media, but even so, the wheel with gas nitriding still could keep a satisfactory adhesive coefficient between the wheel/rail systems, which can prevent the occurrence of phenomena such as wheel-slip. In short, the gas nitriding on the wheel surface can effectively reduce the wear, and improve the rolling contact fatigue resistance of the wheel/rail system. This study enlarges the application field of gas nitriding and provides a new method for the surface protection of railway wheels in heavy-duty transportation.

On the wheel rolling contact fatigue of high power AC locomotives running in complicated environments

Wear ◽  
2019 ◽  
Vol 436-437 ◽  
pp. 202956 ◽  
Author(s):  
Yongfeng Liu ◽  
Tao Jiang ◽  
Xin Zhao ◽  
Zefeng Wen ◽  
Shulin Liang
Keyword(s):  
High Power ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wheel Rolling

Dry and lubricated wear of rail steel under rolling contact fatigue - Wear mechanisms and crack growth

Wear ◽  
2017 ◽  
Vol 380-381 ◽  
pp. 240-250 ◽  
Author(s):  
Santiago Maya-Johnson ◽  
Juan Felipe Santa ◽  
Alejandro Toro
Keyword(s):  
Crack Growth ◽  
Wear Mechanisms ◽  
Rail Steel ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Fatigue Wear

Influence of Track Properties on Railway Vehicles Wheel Rolling Contact Fatigue

2008 ◽  
Author(s):  
Mahdi Mehrgou ◽  
Asghar Nasr
Keyword(s):  
Rolling Contact Fatigue ◽  
Tangential Force ◽  
Contact Fatigue ◽  
Contact Forces ◽  
Rolling Contact ◽  
Vehicle Dynamic ◽  
Wheel Load ◽  
Wheel Rolling ◽  
Railway Passenger ◽  
Vehicle Dynamic Simulation

Track properties such as rail inclination, cant and gage width have significant effects on the shape and size of the contact area, actual rolling radius and also on the contact forces. These effects have an important role on rolling contact fatigue (RCF) which is known to be the main reason for large portion of wheel set failures and expenses. In this study the wheel/rail dynamic interaction of an Iranian railway passenger wagon under different track features are investigated through simulations using ADAMS\Rail commercial software. The calculated results regarding contact load data and contact properties of the wheel and rail are used for fatigue analysis to calculate RCF damage to the wheels using damage criteria based on previous studies. Two major parameters believed to have serious roles on RCF are the contact stress and the tangential force in the contact patch. These parameters are obtained from vehicle dynamic simulation studies. This paper describes and compares effects of different track geometries in curved and tangent tracks on RCF of three different wheel profiles S1002, P8 and IR1002. It is to identify which combinations of wheel load, wheel and rail profiles and vehicle dynamic characteristics cause RCF more severely.

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