Analysis of Wheel-Rail Elasto-Plastic Contact Problem

2002 ◽  
Author(s):  
Jun Zhang ◽  
Yingxi Liu ◽  
Changhua Wu
Keyword(s):  
Finite Element ◽  
Contact Problem ◽  
Contact Problems ◽  
Internal Force ◽  
Rolling Contact ◽  
Tractive Force ◽  
Parametric Quadratic Programming ◽  
Friction Factors ◽  
Quadratic Programming Method ◽  
Parametric Quadratic Programming Method

Using the finite element parametric quadratic programming method, computation of Elastic and Elastic-plastic rolling contact problems between wheel and rail is carried out for various cases such as different wheel diameters, different axle loads, different tractive force and different friction factors. The contact states and the contact internal force between wheel and rail are obtained, and their changing laws corresponding with every above-mentioned parameter are analyzed in this paper.

Hertz Contact Problem between Wheel and Rail

2013 ◽  
Vol 837 ◽  
pp. 733-738 ◽  
Author(s):  
Tiberiu Axinte
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Contact Problem ◽  
Contact Pressure ◽  
Three Dimensional ◽  
Contact Problems ◽  
Rolling Contact ◽  
Hertz Contact ◽  
Shakedown Limit ◽  
Plastic Shakedown

Rail-wheel contact problems have been analyzed by the use of the three-dimensional finite element models. Based on these models, the paper presents a study regarding the applicability of the Hertz contact to rail-wheel contact problems. Beside a standard rail, the study also considers a crane rail and a switching component. The bodies of the contact problem are the standard rail UIC60 and the standard wheel UICORE. The maximum contact pressure which the material can support in the elastic range in steady state conditions is known as the shakedown limit. With an operating contact pressure below the shakedown limit the rail would be expected to remain elastic a long period of its lifecycle. However, examination of rail cross-sections shows severe plastic deformation in a sub-surface layer of a few tens of microns thickness; the contact patch size is in tens of millimeters. Three-dimensional elastic-plastic rolling contact stress analysis was conducted incorporating elastic and plastic shakedown concepts. The Hertzian distribution was assumed for the normal surface contact load over a circular contact area. The tangential forces in both the rolling and lateral directions were considered and were assumed to be proportional to the Hertzian pressure. The elastic and plastic shakedown limits obtained for the three-dimensional contact problem revealed the role of both longitudinal and lateral shear traction on the shakedown results. An advanced cyclic plasticity model was implemented into a finite element code via the material subroutine. Finite element simulations were conducted in order to study the influences of the tangential surface forces in the two shear directions on residual stresses and residual strains. The Hertz theory is restricted to frictionless surfaces and perfectly elastic solids, but it is the best method for determining deformations and stress from pitch of contact. Form change due to wear and plastic deformation of a rail can reduce the service life of a track. The purpose of this investigation was to study the development of these damage mechanisms on new and three years old rails in a commuter track over a period of two years.

scholarly journals The Indentation Rolling Resistance in Belt Conveyors: A Model for the Viscoelastic Friction

Lubricants ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 58 ◽  
Author(s):  
Nicola Menga ◽  
Francesco Bottiglione ◽  
Giuseppe Carbone
Keyword(s):  
Contact Problem ◽  
Finite Thickness ◽  
Numerical Procedure ◽  
Contact Problems ◽  
Accurate Solution ◽  
Rolling Contact ◽  
Viscoelastic Layer ◽  
Force Coefficient ◽  
Belt Conveyors ◽  
Energy Dissipated

In this paper, we study the steady-state rolling contact of a linear viscoelastic layer of finite thickness and a rigid indenter made of a periodic array of equally spaced rigid cylinders. The viscoelastic contact model is derived by means of Green’s function approach, which allows solving the contact problem with the sliding velocity as a control parameter. The contact problem is solved by means of an accurate numerical procedure developed for general two-dimensional contact geometries. The effect of geometrical quantities (layer thickness, cylinders radii, and cylinders spacing), material properties (viscoelastic moduli, relaxation time) and operative conditions (load, velocity) are all investigated. Physical quantities typical of contact problems (contact areas, deformed profiles, etc.) are calculated and discussed. Special emphasis is dedicated to the viscoelastic friction force coefficient and to the energy dissipated per unit time. The discussion is focused on the role played by the deformation localized at the contact spots and the one in the bulk of the thin layer, due to layer bending. The model is proposed as an accurate solution for engineering applications such as belt conveyors, in which the energy dissipated on the rolling contact of idle rollers can, in some cases, be by far the most important contribution to their energy consumption.

3-D Elasto-Plastic Contact Finite Element Analysis for Bearings Design

1990 ◽  
Author(s):  
Wang Shigang ◽  
Yu Jun ◽  
Zhou Ji ◽  
Li Mingzhang
Keyword(s):  
Finite Element ◽  
Contact Problem ◽  
Geometrical Nonlinearity ◽  
Contact Problems ◽  
Plastic State ◽  
Element Analysis ◽  
Surface Pressure Distribution ◽  
Tangential Stiffness ◽  
Stiffness Method ◽  
Error Method

Abstract In this paper, A 3-D elasto-plastic contact problem in bearings is studied by Finite Element Method (FEM). A computer program has been developed for this purpose. A trial-error method is employed to cope with the geometrical nonlinearity and a tangential stiffness method is employed to tackle the material nonlinearity appeared in elasto-plastic contact problems. A frictionless contact problem of roller bearings is analysed, the result reveals that in 3-D elasto-plastic state the trend of the contact surface pressure distribution is similar to Hertz problem’s but flater.

A solution of transient rolling contact with velocity dependent friction by the explicit finite element method

2016 ◽  
Vol 33 (4) ◽  
pp. 1033-1050 ◽  
Author(s):  
Xin Zhao ◽  
Zili Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Problem ◽  
Rolling Contact ◽  
Explicit Finite Element Method ◽  
Content Type ◽  
Explicit Finite Element ◽  
Friction Law ◽  
Transient Rolling ◽  
Element Method

Purpose – The purpose of this paper is to develop a numerical approach to solve the transient rolling contact problem with the consideration of velocity dependent friction. Design/methodology/approach – A three dimensional (3D) transient FE model is developed in elasticity by the explicit finite element method. Contact solutions with a velocity dependent friction law are compared in detail to those with the Coulomb’s friction law (i.e. a constant coefficient of friction). Findings – The FE solutions confirm the negligible influence of the dependence on the normal contact. Hence, analysis is focussed on the tangential solutions under different friction exploitation levels. In the trailing part of the contact patch where micro-slip occurs, very high-frequency oscillations are excited in the tangential plane by the velocity dependent friction. This is similar to the non-uniform sliding or tangential oscillations observed in sliding contact. Consequently, the micro-slip distribution varies greatly with time. However, the surface shear stress distribution is quite stable at different instants, even though it significantly changes with the employed friction model. Originality/value – This paper proposes an approach to solve the transient rolling contact problem with the consideration of velocity dependent friction. Such a problem was usually solved in the literature by the simplified contact algorithms, with which detailed contact solutions could not be obtained, or with the assumption of steady rolling.

Comparison of calculation methods for wheel–switch rail normal and tangential contact

2016 ◽  
Vol 231 (2) ◽  
pp. 148-161 ◽  
Author(s):  
Jingmang Xu ◽  
Ping Wang ◽  
Xiaochuan Ma ◽  
Jieling Xiao ◽  
Rong Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Problems ◽  
Rolling Contact ◽  
The Finite Element Method ◽  
Normal Contact ◽  
Tangential Contact ◽  
Contact Models ◽  
Railway Turnout ◽  
Element Method

Wheel–rail contact is more complex in railway a turnout than in ordinary track and, thus, necessitates an advanced model to simulate dynamic interaction and predict rail wear. The main aim of the present work is to assess the application of several wheel–rail rolling contact models in railway turnout. For normal contact problems, wheel–rail contact models based on four different methods are compared: Hertz theory, the semi-Hertzian method, CONTACT, and the finite element method. The assessment is based on the results of contact patch shape and size and contact pressure for several wheelset lateral displacements. The load is set to a constant and equal to static wheel load. Calculations are performed at the section of switch rail head with width 35 mm in CN60-1100-1:18 turnout; both standard and worn rail profiles are accounted for. For tangential contact problems, four corresponding methods are assessed, based on the calculation of creep forces, distribution of the stick/slide region and computational efficiency: Shen–Hedrick–Elkins theory, FASTSIM, improved FASTSIM based on semi-Hertzian method, and CONTACT. It is found that the normal contact problems solved by the semi-Hertzian method and CONTACT correlate well with the finite element method, and the tangential contact problems solved by improved FASTSIM and CONTACT are quite favorable. The conclusions of this work can provide some guidance for contact model selection in the dynamic simulation and wear prediction of railway turnout.

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