A finite element analysis-based study on the dynamic wheel–rail contact behaviour caused by wheel polygonization

Author(s):  
Kai Liu ◽  
Lin Jing

In this study, an explicit finite element analysis method was adopted to investigate the wheel–rail impact response generated by wheel polygonization, using a three-dimensional wheel–rail rolling contact finite element model. In this model, the infrastructure below the rails and the stiffness and damping of the sleeper supports were considered. Then, the characteristics of the wheel–rail contact zone, the stress/strain state and the wheel–rail impact force of the polygonal wheel–rail system were presented and discussed and were compared with those of the ideally perfect wheel–rail system. A parametrical study was then carried out to examine the influences of train speed and the polygonal order of the wheel on the wheel–rail impact response. The finite element analysis results revealed that the vertical wheel–rail impact force induced by wheel polygonization is related to the wheel radial deviation; the maximum contact force, stress and strain are all elevated with the increase of the order of the polygonal wheel, which suggested that the wheel should be repaired when it is in the initial lower order polygonal state. These findings can provide some theoretical and technical support for the optimal design of the wheel–rail system and the safe operation of high-speed trains.

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.


2015 ◽  
Vol 764-765 ◽  
pp. 289-293
Author(s):  
Yi Chang Wu ◽  
Han Ting Hsu

This paper presents the magnetostatic field analysis of a coaxial magnetic gear device proposed by Atallah and Howe. The structural configuration and speed reduction ratio of this magnetic gear device are introduced. The 2-dimensional finite-element analysis (2-D FEA), conducted by applying commercial FEA software Ansoft/Maxwell, is performed to evaluate the magnetostatic field distribution, especially for the magnetic flux densities within the outer air-gap. Once the number of steel pole-pieces equals the sum of the pole-pair numbers of the high-speed rotor and the low-speed rotor, the coaxial magnetic gear device possesses higher magnetic flux densities, thereby generating greater transmitted torque.


2008 ◽  
Vol 575-578 ◽  
pp. 1461-1466
Author(s):  
Byeong Choon Goo ◽  
Jung Won Seo

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.


Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.


1999 ◽  
Vol 36 (04) ◽  
pp. 203-210
Author(s):  
Steven P. McGee ◽  
Armin Troesch ◽  
Nickolas Vlahopoulos

In 1994 the International Maritime Organization adopted the Code of Safety for High-Speed Craft (HSC Code). After two years of use, several shortfalls were found, one being the damage length predictor, which is based on traditional steel, mono-hulled vessels. Other damage predictors were developed based on historical data, but they do not account for variables such as aluminum or fiberglass construction, transverse members, indenter geometry variation, or for the case where the vessel comes to rest on the grounding object. This paper proposes a damage prediction model based on material properties, structural layout, grounding object geometry, and vessel speed. The model incorporates four grounding mechanisms: plate cutting, plate tearing, crushing of plate behind transverse members, and transverse member failure. The method is used to determine the resistance energy, compared to the kinetic energy, of the vessel, to determine an effective damage length. Finite-element analysis was used to model the failure of both aluminum and steel transverse members with significant differences in the results. It was found that the transverse members provided the majority of the resistance energy in one grounding mechanism and negligible resistance energy in another.


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