Observation and Simulation of Axle Box Acceleration in the Presence of Rail Weld in High-Speed Railway

Abstract

Rail welds are widely used in high-speed railways and short-wave irregularities usually appear due to limitations in welding technology. These irregularities can excite a high wheel/rail force and are regarded as the main cause of deterioration in track structures. To measure this fierce force (or deterioration of the rail weld), axle box acceleration is treated as an effective and economic measure, though an exact quantitative relation between these two quantities remains elusive. This paper aims to develop such a relation in order to provide a new theoretical basis and an analysis method for monitoring and controlling weld geometry irregularity. To better understand the characteristics of axle box acceleration, the paper consists of two parts: an observation and a numerical simulation of axle box acceleration by rail welds. Based on measured data from field tests, axle box acceleration at rail welds was found to have high-frequency vibrations in two frequency bands (i.e., 350-500 Hz and 1000-1200 Hz). Upon analyzing the vibration characteristics in time-frequency domains, the exact location of the rail weld irregularity could be identified. Subsequently, a 3D high-speed wheel/rail rolling contact finite element model was employed to investigate the effect of rail weld geometry on axle box acceleration, and led to the discovery that the weld length and depth determine the vibration frequency and amplitude of the axle box acceleration, respectively. A quantitative relation between axle box acceleration and wheel/rail force has also been determined. Finally, we propose an approach for real-time health detection of rail welds and discuss the influence of other defects and rail welds on the acceleration signal of the axle box.

An Innovative and Efficient Method for Reverse Design of Wheel-Rail Profiles

“…The contrast analysis shows that when the lateral displacement reaches 6 mm, the maximum contact stress will be distributed evenly and can be decreased by 184. 4 MPa compared to that of existing profiles. The critical speed can be increased by 10.8% compared to that of existing profiles.…”

“…For railway vehicles, the proper design of wheel-rail profiles is helpful in achieving ideal vehicle operation, including curve negotiation, prevention of derailment, running stability and safety [1][2][3][4]. The design of wheel-rail profiles has been a topic of concern in many studies and many profile design methods with different targets and measures have been presented.…”

Parameters Studies on Surface Initiated Rolling Contact Fatigue of Turnout Rails by Three-Level Unreplicated Saturated Factorial Design

“…Therefore, establishing a model for simulating and predicting this fatigue through generating random samples for dynamic parameters of the vehicle-turnout system and presenting a superimposition and accumulation method for rail surface initiated RCF damage is expected for further work. In addition, with the development of computer technology and finite element theory, some complicated wheel-rail rolling contact problems have been solved by the explicit finite element method [38,39]. Therefore, investigation of turnout rail surface initiated RCF behavior using this method is also the next step in the future works.…”

Numerical Investigation into the Effect of Geometric Gap Idealisation on Wheel‐Rail Rolling Contact in Presence of Yaw Angle

“…More advanced FE model is developed by Zhao and Li [20] and further applied for computing nonsteady rolling contact due to yaw angle [21]. Similar FE models are also developed by Pletz [22], An [23], Zong and Dhanasekar [24]. However, high time consuming restricts this kind of FE model to be applied for engineering application, which usually needs more than ten hours to finish a case.…”