scholarly journals Investigation on Wheel-Rail Contact and Damage Behavior in a Flange Bearing Frog with Explicit Finite Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Yuan Gao ◽  
Ping Wang ◽  
Yibin Liu ◽  
Jingmang Xu ◽  
Zhiguo Dong ◽  
...  
Keyword(s):  
Finite Element ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Numerical Procedure ◽  
Contact Forces ◽  
Rolling Contact ◽  
Fe Model ◽  
Wheel Load ◽  
Explicit Finite Element ◽  
Contact Behavior

Flange bearing frogs are designed to provide continuous rolling surfaces for trains traveling on the through line, but the interaction between wheel and rail in a diverging line is more complex than that for a common crossing, especially including flange bearing mode and multipoint contact during the transition. The wheel load will be transited from tread to flange and back to tread, which will intensify the wheel-rail interaction. In this paper, a numerical procedure is presented for the analysis of wheel-rail rolling contact behavior and damage prediction for the flange bearing frog. The three-dimensional explicit finite element (FE) model of a wheel passing the flange bearing frog is established to obtain the dynamic wheel-rail interaction in both the facing and the trailing move. The evolution of contact forces, the distribution of adhesion-slip regions, and shear surface stress and microslip at the contact patch are revealed. Then, the competition relationship between RCF (rolling contact fatigue) and wear of a flange bearing frog is analyzed. The results of numerical simulations can contribute to an understanding of the mechanism of the transient rolling contact behavior and provide guidance in design optimization for flange bearing frogs.

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.

Investigating the Rolling Contact Fatigue in Rails Using Finite Element Method and Cohesive Zone Approach

2018 ◽  
Author(s):  
Mohamad Ghodrati ◽  
Mehdi Ahmadian ◽  
Reza Mirzaeifar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Grain Boundaries ◽  
Fatigue Damage ◽  
Cohesive Zone ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wheel Load ◽  
Element Method

A micromechanical-based 2D framework is presented to study the rolling contact fatigue (RCF) in rail steels using finite element method. In this framework, the contact patch of rail and wheel is studied by explicitly modeling the grains and grain boundaries, to investigate the potential origin of RCF at the microstructural level. The framework incorporates Voronoi tessellation algorithm to create the microstructure geometry of rail material, and uses cohesive zone approach to simulate the behavior of grain boundaries. To study the fatigue damage caused by cyclic moving of wheels on rail, Abaqus subroutines are employed to degrade the material by increasing the number of cycles, and Jiang-Sehitoglu fatigue damage law is employed as evolution law. By applying Hertzian moving cyclic load, instead of wheel load, the effect of traction ratio and temperature change on RCF initiation and growth are studied. By considering different traction ratios (0.0 to 0.5), it is shown that increasing traction ratio significantly increases the fatigue damage. Also by increasing traction ratio, crack initiation migrates from the rail subsurface to surface. The results also show that there are no significant changes in the growth of RCF at higher temperatures, but at lower temperatures there is a measurable increase in RCF growth. This finding correlates with anecdotal information available in the rail industry about the seasonality of RCF, in which some railroads report noticing more RCF damage during the colder months.

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.

Applications for a New Production Technology: Analysis of Linear Flow-Split Linear Guides

2012 ◽  
Author(s):  
Ivan Karin ◽  
Nils Lommatzsch ◽  
Klaus Lipp ◽  
Volker Landersheim ◽  
Holger Hanselka ◽  
...  
Keyword(s):  
Finite Element ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Material Behavior ◽  
Research Centre ◽  
Fe Model ◽  
Linear Flow ◽  
Guidance Systems ◽  
Calculation Models

Within the collaborative research centre 666 “Integral Sheet Metal Design with Higher Order Bifurcations” the innovative manufacturing technologies linear flow-splitting and linear bend-splitting are researched that allow the continuous production of multi-chambered steel profiles in integral style. The massive forming processes create an ultra-fine grained microstructure in the forming area that is characterized by an increased hardness and lower surface roughness compared to as received material. These properties predestine the technology to be used in the production of linear guides. Additionally, the multi-chambered structure of the linear flow-split and -bend components can be used for function integration. To design and evaluate linear guides that use the whole technological potential, the research is focused on a macroscopic and a microscopic point of view. The macroscopic approach is targeting the development of linear flow-split linear guides with integrated functions to provide additional performance values to the established machine parts. Continuously produced guidance systems with innovative functionality can be introduced to a new market with the technology push approach. Preliminary designs of linear flow-split guidance systems and integrated functions are promising. Therefore, an approach to develop new functions for linear flow-split linear guides basing on calculation models and property networks is shown [1]. With this approach, optimized solutions can be created and possible design modifications can be derived. In this contribution, the development and integration of a clamping function for decelerating the slide is presented. Calculation models for analyzing the functionality are presented and validated by finite element models and experiments. The microscopic examination of the profiles aims to investigate the material behavior, particularly of the formed areas. Beside the conventional mechanical and fatigue properties of linear flow-split material ZStE500 [2], the present work focuses on the rolling contact fatigue. This is necessary to evaluate linear flow-split components regarding their eligibility with regard to the rolling contact fatigue behaviour. The Hertz theory for rolling contact fatigue is only valid for homogeneous materials [3]. The flow-split material ZStE500 shows a non-homogeneous behaviour and has to be analyzed with the Finite Element Method in order to determine stresses and strains. In comparison to simulation results with unformed and therefore homogeneous material, the effect of linear flow-split surfaces on the rolling contact behavior is demonstrated. Based on these results, it is possible to start experimental investigations on rolling contact fatigue of linear flow-split components to validate the FE model and determine the performance of linear flow-split flanges for rolling contact fatigue.

Influence of Short-Pitch Wheel/Rail Corrugation on Rolling Contact Fatigue of Railway Wheels

2005 ◽  
Vol 219 (3) ◽  
pp. 177-187 ◽  
Author(s):  
J C O Nielsen ◽  
A Ekberg ◽  
R Lundén
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Numerical Procedure ◽  
Contact Forces ◽  
Rolling Contact ◽  
Rail Corrugation ◽  
Low Pass ◽  
Railway Wheels

A numerical procedure to integrate simulation of high-frequency dynamic train-track interaction and prediction of rolling contact fatigue (RCF) impact is presented. Features of the included models and possibilities of applications are outlined. The influence of short-pitch rail corrugation and wheel out-of-roundness (OOR) on RCF of a high-speed passenger train is investigated. It is shown how the corrugation and the OOR will have a profound effect in that levels of wheel and rail irregularities that have been measured in the field may be sufficient to generate subsurface-initiated RCF. In particular, the high-frequency content of the contact forces is of importance. Errors induced by neglecting such high-frequency components in measurements and/or simulations are investigated by comparing RCF indices based on contact forces that have been low-pass filtered with various cut-off frequencies. To avoid cracking due to RCF, a maximum roughness level in the wavelength interval up to 10 cm is sought. To limit the effects of corrugation, grinding practices have been altered leading to a significant decrease in RCF.

The Effects of Wheelset Position and Operating Environment on Rolling Contact Fatigue

2008 ◽  
Author(s):  
Scott M. Cummings ◽  
Paul Krupowicz
Keyword(s):  
Environmental Factors ◽  
Impact Load ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Contact Forces ◽  
Rolling Contact ◽  
Minor Role ◽  
Operating Environment ◽  
Lead Position ◽  
Defect Prevention

The Wheel Defect Prevention Research Consortium (WDPRC) conducted analyses of wheel impact load detector (WILD) data to explore how wheelset position and operating environment affect rolling contact fatigue (RCF). The typical three-piece freight car truck used in North America produces higher tangential wheel/rail contact forces on the wheelset in the lead position than on the wheelset in the trail position of a truck as a car negotiates a curve. An analysis of WILD data shows that these higher forces are contributing to more shelling damage on wheelsets that are consistently in the lead position of a truck. Datasets in which the cars are frequently oriented with the A-end leading show the largest percentage of elevated WILD readings in the lead position of the lead truck (axle 4) followed by the lead position of the trail truck (axle 2). Likewise, datasets in which the cars are frequently oriented with the B-end leading show the largest percentage of elevated WILD readings in the lead position of the lead truck (axle 1) followed by the lead position of the trail truck (axle 3). Additionally, datasets in which there is an equal mix of car orientations show a much more evenly distributed location of elevated WILD readings. Another analysis of WILD data from five trainsets of nearly identical cars shows that any differences in wheel tread damage due to component differences are insignificant in comparison to the differences in wheel tread damage associated with environmental factors. While this analysis does not address component specification differences that could potentially have a large influence on shelling (such as M-976 trucks in comparison to standard trucks), it does show that environmental factors can play a large role in wheel tread damage. Car routing and loading characteristics were investigated as possible wheel damage factors. It appears that cars running on routes through terrain with longer, steeper grades may be prone to increased wheel shelling, probably due to thermal mechanical shelling (TMS). Side-to-side imbalanced loading appears to play a minor role in wheel shelling for two of the five trainsets.

Thermal Effects on Wheel Performance Based on Twin Disc Testing

2020 ◽  
Author(s):  
Dingqing Li ◽  
Monique Stewart
Keyword(s):  
Thermal Effects ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Contact Forces ◽  
Rolling Contact ◽  
Test Machine ◽  
Testing Program ◽  
Different Types ◽  
Different Temperatures ◽  
Surface Performance

Abstract This paper presents the results and findings from a testing program conducted to investigate how temperature at the wheel-rail interface may affect wheel surface performance; i.e., development of rolling contact fatigue (RCF) and wear. Under this testing program, a twin disc test machine was used to test two different types of wheel specimens (cast and forged) under a range of temperatures (ambient to 800° F) and slip ratios from 0 to 0.75 percent. This testing program included a total of 32 tests, covering two wheel materials, four different temperatures, four slip ratios, and various traction coefficients as a ratio of longitudinal and vertical wheel/rail contact forces.

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