A Direct Analysis of Three-Dimensional Elastic-Plastic Rolling Contact

1995 ◽  
Vol 117 (2) ◽  
pp. 234-243 ◽  
Author(s):  
Maria M.-H. Yu ◽  
Brian Moran ◽  
Leon M. Keer
Keyword(s):  
Finite Element ◽  
Plane Problem ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Yield Condition ◽  
Rolling Contact ◽  
Direct Approach ◽  
Hardening Material ◽  
Elastic Plastic ◽  
Residual Problem

A novel treatment of a direct procedure for elastic-plastic analysis and shakedown is presented and its application to problems in three-dimensional rolling contact with or without case-hardened layers is demonstrated. The direct approach consists of an operator split technique, which transforms the elastic-plastic problem into a purely elastic problem and a residual problem with prescribed eigenstrains. These eigenstrains are determined using an incremental projection method based on the purely elastic solution and a special representation of the yield condition for a linear-kinematic hardening material. The three-dimensional residual problem is then further split into a plane problem and an anti-plane problem which are readily solved using the finite element method. A significant advantage of the present analysis over the alternative approach of simulating repeated rolling until shakedown occurs is that in the present analysis, the final shakedown solution is obtained directly by solving three elasticity problems. Results are compared with full elastic-plastic finite element calculations available from the literature and good agreement is observed. The effects of surface hardened layers on the distributions of residual stress and displacement are investigated for both two- and three-dimensional contact. The direct approach is shown to be a straightforward and efficient method for obtaining the steady state solution in the analysis of three-dimensional problems in rolling and/or sliding contact.

A Direct Analysis of Two-Dimensional Elastic-Plastic Rolling Contact

1993 ◽  
Vol 115 (2) ◽  
pp. 227-236 ◽  
Author(s):  
M. Yu ◽  
B. Moran ◽  
L. M. Keer
Keyword(s):  
Finite Element ◽  
Direct Analysis ◽  
Rolling Contact ◽  
Direct Approach ◽  
Two Dimensional ◽  
Elastic Plastic ◽  
Finite Element Calculations ◽  
Plastic Analysis ◽  
Plastic Shakedown ◽  
Residual Problem

A direct approach for elastic-plastic analysis and shakedown is presented and its application to a two-dimensional rolling contact problem is demonstrated. The direct approach consists of an operator split technique, which transforms the elastic-plastic problem into a purely elastic problem and a residual problem with prescribed eigenstrains. The eigenstrains are determined using an incremental projection method which is valid for nonproportional loading and both elastic and plastic shakedown. The residual problem is solved analytically and also by using a finite element procedure which can be readily generalized to more difficult problems such as three-dimensional rolling point contact. The direct analysis employs linear-kinematic-hardening plastic behavior and thus either elastic or plastic shakedown is assured, however, the phenomenon of ratchetting which can lead to incremental collapse, cannot be treated within the present framework. Results are compared with full elastic-plastic finite element calculations and a step-by-step numerical scheme for elastic-plastic analysis. Good agreement between the methods is observed. Furthermore, the direct method results in substantial savings in computational effort over full elastic-plastic finite element calculations and is shown to be a straightforward and efficient method for obtaining the steady state (shakedown) solution in the analysis of rolling and/or sliding contact.

Elasto-Plastic Finite Element Analysis of Repeated Three-Dimensional, Elliptical Rolling Contact With Rail Wheel Properties

1991 ◽  
Vol 113 (3) ◽  
pp. 434-441 ◽  
Author(s):  
S. M. Kulkarni ◽  
G. T. Hahn ◽  
C. A. Rubin ◽  
V. Bhargava
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Half Space ◽  
Kinematic Hardening ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Rolling Contact ◽  
Cyclic Plasticity ◽  
Wheel Load ◽  
Stress Strain

This paper presents an elasto-plastic analysis of the repeated, frictionless, three-dimensional rolling contact similar to the ones produced by the rail-wheel geometry. This paper treats an elliptical contact rolling across a semi-infinite half space. The contact shape and loading: semi-major axis (in the rolling direction), w1 = 8 mm, and semi-minor axis, w2 = 5.88 mm, reflect standard rail and wheel curvatures and a wheel load of 149 KN (33,000 lb). A three-dimensional, elasto-plastic finite element model, developed earlier, is employed together with the elastic-linear-kinematic-hardening-plastic (ELKP) idealization of the cyclic plastic behaviour of a material similar to rail and wheel steels. The calculations present the displacements, the stress-strain distributions, stress-plastic strain histories and the plastic strain ranges in the half-space. The cyclic plasticity approaches a steady state after one contact with further contacts producing open but fully reversed stress-strain hysteresis loops, i.e., plastic shakedown.

Elasto-Plastic Finite Element Analysis of Three-Dimensional Pure Rolling Contact Above the Shakedown Limit

1991 ◽  
Vol 58 (2) ◽  
pp. 347-353 ◽  
Author(s):  
S. M. Kulkarni ◽  
G. T. Hahn ◽  
C. A. Rubin ◽  
V. Bhargava
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Bearing Steel ◽  
Complex Stress State ◽  
Rolling Contact ◽  
Stress Strain ◽  
Element Analysis ◽  
Shakedown Limit

This paper describes calculations for repeated, frictionless, three-dimensional rolling contact, for a relative peak pressure (po/k) of 6.0 (above the shakedown limit) for a circular contact patch. This analysis was carried out for two material responses, elastic-perfectly plastic (EPP) and elastic-linear-kinematic-hardening plastic (ELKP), using the elasto-plastic finite element model developed earlier. The ELKP material parameters are those appropriate for hardened bearing steel. Frictionless three-dimensional rolling contact is simulated by repeatedly translating a Hertzian pressure distribution across the surface of an elasto-plastic half space. The half space is represented by a finite mesh with elastic boundaries. The paper describes the complex stress state existing in the half space and the attending plasticity, as the load translates. The calculations present the distortion of the rim, the residual stress-strain distributions, stress-strain histories, and the cyclic plastic strain increments in the vicinity of the contact. Compared with the analyses at the shakedown limit, higher residual stresses and strains are observed.

A numerical study on effects of friction-induced thermal load for rail under varied wheel slip conditions

SIMULATION ◽  
2018 ◽  
Vol 95 (4) ◽  
pp. 351-362 ◽  
Author(s):  
Jay Prakash Srivastava ◽  
Prabir Kumar Sarkar ◽  
MV Ravi Kiran ◽  
Vinayak Ranjan
Keyword(s):  
Finite Element ◽  
Temperature Rise ◽  
Thermal Load ◽  
Kinematic Hardening ◽  
Rolling Contact ◽  
Maximum Temperature ◽  
Wheel Slip ◽  
Hardening Material ◽  
Slip Conditions ◽  
Finite Element Software

A finite element-based simulation was carried out to investigate the effects of friction-induced thermal load on rail under varied wheel slip conditions. The surface temperature rise from six different percentage slips (1%, 1.5%, 2%, 5%, 8.5%, and 10%) at the contact interface was examined for eight-wheel pass. The residual stresses and accumulated plastic strains evolved by the effect of localized temperature rise are estimated. Analytical formulation for conduction mode of heat transfer at the contact patch is used to estimate the temperature distribution. The interaction of thermal-elastic-plastic field conditions is obtained by a proposed simulation model. This is implemented in commercial finite element software ANSYS 14.0. In order to capture the steep thermal gradient beneath the contact surface, refined mesh is used in the upper layers up to a depth of 2 mm of the simulation domain. For better manifestation of thermally affected material layers, a temperature dependent bilinear-kinematic hardening material condition is applied. Results indicate the maximum temperature rise at about 0.6 a from the trailing end in the contact ellipse of semi-major axis a. At higher slippage conditions the initial pearlitic rail steel gets converted to martensite which is often observed on rail surface as white etching layer known to be associated with rolling contact fatigue. The study reveals the mechanisms of thermally induced defects observable on rail surface. The outcomes, in addition, can provide useful information for the development of thermo-mechanically superior rail steels.

Three-Dimensional Elastic-Plastic Stress Analysis of Rolling Contact

2002 ◽  
Vol 124 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Yanyao Jiang ◽  
Biqiang Xu ◽  
Huseyin Sehitoglu
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Stress Analysis ◽  
Tangential Force ◽  
Three Dimensional ◽  
Rolling Contact ◽  
Normal Surface ◽  
Elastic Plastic ◽  
Residual Strains ◽  
Plastic Shakedown

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 to study the influences of the tangential surface forces in the two shear directions on residual stresses and residual strains. For all the cases simulated, the p0/k ratio (p0 is the maximum Hertzian pressure and k is the yield stress in shear) was 6.0. The Qx/P ratio, where Qx is the total tangential force on the contact surface in the rolling direction and P is the total normal surface pressure, ranged from 0 to 0.6. The Qy/P ratio (Qy is the total tangential force in the lateral direction) was either zero or 0.25. Residual stresses increase with increasing rolling passes but tend to stabilize. Residual strains also increase but the increase in residual strain per rolling pass (ratchetting rate) decays with rolling cycles. Residual stress levels can be as high as 2k when the Qx/P ratio is 0.6. Local accumulated shear strains can exceed 20 times the yield strain in shear after six rolling passes under extreme conditions. Comparisons of the two-dimensional and three-dimensional rolling contact results were provided to elucidate the differences in residual stresses and ratchetting strain predictions.

Three-Dimensional Finite Element Elastic–Plastic Model for Subsurface Initiated Spalling in Rolling Contacts

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
John A. R. Bomidi ◽  
Farshid Sadeghi
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Fatigue Damage ◽  
Three Dimensional ◽  
Rolling Contact ◽  
Material Behavior ◽  
Lower Percentage ◽  
Fe Model ◽  
Plastic Model ◽  
Elastic Plastic

In this investigation, a three-dimensional (3D) finite element (FE) model was developed to study subsurface initiated spalling observed in rolling line contact of tribo components such as bearings. An elastic–kinematic hardening–plastic material model is employed to capture the material behavior of bearing steel and is coupled with the continuum damage mechanics (CDM) approach to capture the material degradation due to fatigue. The fatigue damage model employs both stress and accumulated plastic strain based damage evolution laws for fatigue failure initiation and propagation. Failure is modeled by mesh partitioning along unstructured, nonplanar, intergranular paths of the microstructure topology represented by randomly generated Voronoi tessellations. The elastic–plastic model coupled with CDM was used to predict both ratcheting behavior and fatigue damage in heavily loaded contacts. Fatigue damage induced due to the accumulated plastic strains around broken intergranular joints drive the majority of the crack propagation stage, resulting in a lower percentage of life spent in propagation. The 3D FE model was used to determine fatigue life at different contact pressures ranging from 2 to 4.5 GPa for 33 different randomly generated microstructure topology models. The effect of change in contact pressure due to subsurface damage and plastic strain accumulation was also captured by explicitly modeling the rolling contact geometry and the results were compared to those generated assuming a Hertzian pressure profile. The spall shape, fatigue lives, and their dispersion characterized by Weibull slopes obtained from the model correlate well with the previously published experimental results.

A Three-Dimensional Finite Element Analysis of the Cold Forging of a Model Aluminium Connecting Rod

1985 ◽  
Vol 199 (4) ◽  
pp. 319-324 ◽  
Author(s):  
I Pillinger ◽  
P Hartley ◽  
C E N Sturgess ◽  
G W Rowe
Keyword(s):  
Computer Simulation ◽  
Finite Element ◽  
Strain Hardening ◽  
Metal Flow ◽  
Three Dimensional ◽  
Cold Forging ◽  
Connecting Rod ◽  
Element Analysis ◽  
Hardening Material ◽  
Elastic Plastic

A fully three-dimensional elastic-plastic finite element method is used to simulate metal flow during the most complex stage of the cold forging of a model of an aluminium connecting rod. The results of the computer simulation are compared with the forging of strain-hardening aluminium billets using graphite lubrication. The analysis predicts deformation patterns and hardness distributions which have been checked by selected experiments. The experimental results show inhomogeneous deformation in various parts of the forging and noticeable variations in the formation of flash around its periphery, features which are also found in the analyses. The elastic-plastic finite element technique can thus satisfactorily be applied to three-dimensional forgings of strain-hardening material. The work described here represents one part of a continuing research programme to develop computer simulation techniques for the modelling of complex cold, warm or hot industrial forgings.

Elastoplastic Finite Element Analysis of Three-Dimensional, Pure Rolling Contact at the Shakedown Limit

1990 ◽  
Vol 57 (1) ◽  
pp. 57-65 ◽  
Author(s):  
S. M. Kulkarni ◽  
G. T. Hahn ◽  
C. A. Rubin ◽  
V. Bhargava
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Element Model ◽  
Rolling Contact ◽  
Stress Strain ◽  
Element Analysis ◽  
Perfectly Plastic ◽  
Shakedown Limit

This paper describes a three-dimensional elastoplastic finite element model of repeated, frictionless rolling contact. The model treats a sphere rolling on an elastic-perfectly plastic and an elastic-linear-kinematic-hardening plastic, semi-infinite half space. The calculations are for a relative peak pressure (po/k) = 4.68 (the theoretical shakedown limit for perfect plasticity). Three-dimensional rolling contact is simulated by repeatedly translating a hemispherical (Hertzian) pressure distribution across an elastoplastic semi-infinite half space. The semi-infinite half space is represented by a finite mesh with elastic boundaries. The calculations describe the distortion of the rim, the residual stress-strain distributions, stress-strain histories, and the cyclic plastic strain ranges in the vicinity of the contact.

A Coupled Multibody Finite Element Model for Investigating Effects of Surface Defects on Rolling Contact Fatigue

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Zamzam Golmohammadi ◽  
Farshid Sadeghi
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Surface Defects ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Internal Stresses ◽  
Fe Model ◽  
Elastic Plastic ◽  
Pile Up

A coupled multibody elastic–plastic finite element (FE) model was developed to investigate the effects of surface defects, such as dents on rolling contact fatigue (RCF). The coupled Voronoi FE model was used to determine the contact pressure acting over the surface defect, internal stresses, damage, etc. In order to determine the shape of a dent and material pile up during the over rolling process, a rigid indenter was pressed against an elastic plastic semi-infinite domain. Continuum damage mechanics (CDM) was used to account for material degradation during RCF. Using CDM, spall initiation and propagation in a line contact was modeled and investigated. A parametric study using the model was performed to examine the effects of dent sharpness, pile up ratio, and applied load on the spall formation and fatigue life. The spall patterns were found to be consistent with experimental observations from the open literature. Moreover, the results demonstrated that the dent shape and sharpness had a significant effect on pressure and thus fatigue life. Higher dent sharpness ratios significantly reduced the fatigue life.

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