The transient response of high-speed wheel/rail rolling contact on “roaring rails” corrugation

2019 ◽  
Vol 233 (10) ◽  
pp. 1068-1080 ◽  
Author(s):  
Miao Yu ◽  
Wei-dong Wang ◽  
Jin-zhao Liu ◽  
Shan-chao Sun
Keyword(s):  
Finite Element ◽  
High Frequency ◽  
High Speed ◽  
Short Wave ◽  
Rolling Contact ◽  
Explicit Finite Element Method ◽  
Explicit Finite Element ◽  
Rail Corrugation ◽  
Vehicle System ◽  
Steady State Rolling

A high-speed wheel/rail finite element model is developed to focus on the non-steady-state rolling contact. The wheel/rail contact is solved based on the surface-to-surface contact algorithm, and the explicit finite element method is used to simulate the dynamic high-speed wheel/rail rolling contact. Considering the track–vehicle coupling system dynamics and the wheel/rail geometric nonlinearities, the wheel/rail contact on the short wave rail corrugation under the high-frequency vibration and the influence of train passing frequency on the track–vehicle system dynamics are studied. The explicit finite element method can be used to simulate the non-steady-state rolling contact process of the high-speed wheel/rail. After the initial load condition, the wheel/rail contact state tends to be stable in a short period of time. The short wave corrugation causes the high-frequency vibration of the track–vehicle system; the slightly advanced phase of the wheel/rail contact force promotes the development of rail corrugation in the rolling direction. When the train passing frequency is close to the rail pinned–pinned frequency, the pinned–pinned resonance occurs. The overall vibration near the fastening is relatively large and accelerates the damage of components. The longitudinal force is clearly affected by the traction torque with a periodic wheel/rail stick-slip vibration. The pinned–pinned resonance will promote the sliding wear at the wave trough near the fastening and it will become severe with the increase of the traction.

Explicit Finite Element Simulation of Granular Flow in an Annular Shear Cell

2009 ◽  
Author(s):  
M. A. Kabir ◽  
C. F. Higgs ◽  
M. R. Lovell ◽  
V. Jasti ◽  
M. C. Marinack
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Granular Flow ◽  
High Speed ◽  
Flow Behavior ◽  
Shear Cell ◽  
Explicit Finite Element Method ◽  
Explicit Finite Element ◽  
Annular Shear Cell ◽  
Element Method

Explicit finite element method modeling of granular flow behavior in an annular shear cell has been studied and presented in this paper. The explicit finite element method (FEM) simulations of granular flow in an annular shear cell with around 1633 particles were performed, where the inner wheel rotated at a very high speed and the outer disk remained stationary. The material properties of the particles and the outer wheel were defined as elastic steel whereas the inner wheel was elastic aluminum. In this investigation, the explicit FEM model mimicked granular flow in an experimental set up where the inner wheel was rotated at a speed of 240 rpm. The FEM results for shearing motion and solid fraction were compared with experimental results from a granular shear cell.

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.

scholarly journals Research on the relationship between the rail corrugation and the vibration response of the wheel-rail system

2020 ◽  
Vol 308 ◽  
pp. 02002
Author(s):  
Xinyu Jia ◽  
Guoqing Li ◽  
Xiubo Liu ◽  
Peng Chen
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
High Speed ◽  
Rolling Contact ◽  
Common Phenomenon ◽  
Rail Corrugation ◽  
Rail System ◽  
Train Operation ◽  
Transient Rolling ◽  
The Relationship

Rail corrugation is a very common phenomenon in high-speed railways. Rail corrugation can cause increased vibration of trains and tracks, and may even affect the safety of train operation. Therefore, this paper will analyze the vibration of the wheel-rail system caused by the rail corrugation. The actual transient rolling contact model is established by using explicit and implicit finite element methods. Through the calculation of the wheel-rail contact force and the wheel-rail mode, the vibration relationship between the rail corrugation and the wheel-rail system is obtained. It can provide some references for further analysis of the cause of rail corrugation.

Determination of dynamic amplification factors for heavy haul railways

2016 ◽  
Vol 232 (2) ◽  
pp. 514-528 ◽  
Author(s):  
Xin Zhao ◽  
Jizhong Yang ◽  
Boyang An ◽  
Chao Liu ◽  
Yabo Cao ◽  
...  
Keyword(s):  
High Frequency ◽  
Element Model ◽  
Rolling Contact ◽  
Dynamic Amplification Factor ◽  
Explicit Finite Element ◽  
Amplification Factors ◽  
Rail Corrugation ◽  
Heavy Haul ◽  
Dynamic Amplification ◽  
Heavy Haul Railway

A new approach has been developed to determine the dynamic amplification factors of railways. This approach employs a traditional multi-body dynamic model of vehicle–track interaction and a 3D explicit finite element model of wheel–rail rolling contact to treat the low- and high-frequency dynamics, respectively. Excitations are considered by contact surface unevenness and more specifically, by the power spectrum density of track irregularity for the low-frequency analysis and by the critical wheel flat, weld, and rail corrugation for the high frequency. For the 40-tonne axle load heavy haul railway simulated in this work, it has been found that the optimum fastening stiffness should be 150–200 MN/m; the dynamic amplification factors of the wheel–rail contact, fastening, and ballast forces are 1.94, 2.0, and 1.67, respectively, if the fastening stiffness of 200 MN/m is applied. Finally, new dynamic amplification factor formulae that include key parameters such as the fastening stiffness, speed, and axle load are proposed for the heavy haul railway design.

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.

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

2019 ◽  
Vol 234 (10) ◽  
pp. 1285-1298 ◽  
Author(s):  
Kai Liu ◽  
Lin Jing
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
Impact Force ◽  
Rolling Contact ◽  
Impact Response ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Rail System ◽  
Contact Behaviour

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.

The Study on Crashworthiness Performance of Thin-Walled Structures and the Effect of Welding Performance on it

2011 ◽  
Vol 63-64 ◽  
pp. 655-658
Author(s):  
Qi Hao ◽  
Sheng Jun Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Welded Joints ◽  
Impact Force ◽  
Deformation Energy ◽  
Optimal Shape ◽  
Explicit Finite Element Method ◽  
Explicit Finite Element ◽  
Thin Walled Structures ◽  
Thin Walled

Explicit finite element method is adopted to simulate the crashworthiness performance of four types of typical thin—walled structures used in vehicle by software LS-DYNA. The structures with the same material、area and length are crash by a rigid body with 40km/h in10ms, The crash processes and crashworthiness characters are analyzed by a series crash parameters: deformation energy with unit displacement, impact force and deceleration to look for the optimal shape with crashworthiness. With comparing, the double caps section has ascendant performance than the others. The simulating methods of welded-joints are discussed to analysis their effects on crashworthiness simulation.

Sign in / Sign up

Export Citation Format

Share Document