Wayside detection monitors critical parameters relating to the condition of in-service railway vehicles. Economic decisions about the maintenance of vehicles can be made, and servicing can occur wh...

Structural Health Monitoring in the Railway Industry: A Review:

A review of the modelling of wheel/rail noise generation

The influence of different types of railway wheel out-of-roundness (OOR) on the vertical dynamic wheel-rail contact force and track response is investigated through extensive field tests and numerical simulations. The response from a freight train, provided with a number of different types of severe wheel tread damage, is studied. Two different axle loads are used in combination with different train speeds in the range 30-100km/h. The wheel defects are wheelflats, local spalls due to rolling contact fatigue cracking, long local defects and polygonal wheels (periodic OOR). The vertical wheel-rail contact force was measured using a strain gauge based wheel impact load detector. Strain gauges and accelerometers were positioned on rails and sleepers to measure the track response. Most of the magnitudes of measured impact forces were found to be lower than the current impact load limit that is used in Sweden to determine when a defective wheel should be removed for repair. Only the long local defect ca...

Out-of-round railway wheels—wheel-rail contact forces and track response derived from field tests and numerical simulations:

Out-of-round rollingstock wheels are caused by skidding or spalling of the wheel tread and by dynamic motion of wheels and wheelsets in service. Out-of-round wheels generate impact forces at the wheel-rail interface, which are transferred to train and to track components including rail and both bolted and welded rail joints, prestressed concrete sleepers, ballast, wheels, and bearings.To make a rational decision about removing out-of-round wheels from service, estimation of the damage caused by an individual wheel is required. Previous studies have used analytical and numerical models to illustrate the distribution of impact into track and rolling stock components. These models are compared here. The review details mathematical models and studies of the lives of the earlier-listed components, which would provide a means of determining the damage caused by impacting wheels. In addition, studies have found that impacting wheels increase fuel consumption and increase pass-by noise levels, which are a...

A Review of the Effects of Out-of-Round Wheels on Track and Vehicle Components

Out-of-round railway wheels can have a detrimental influence ontrack and vehicle components, contributing to increased risks of rail breaks, sleeper cracking, high-cycle fatigue of wheels and axles and bearing damage. Environmental consequences are rolling noise and impact noise, ground vibrations and passenger discomfort. Causes of different types of out-of-round wheels are surveyed. Experimental equipment and assessment procedures for quantification of out-of-roundness are explained. Results from field tests illustrating consequences of out-of-round wheels are presented. Wheel impact load detectors and examples of alarm limits used in different countries for detection of detrimental wheel defects are listed. Mathematical models and computer programs for simulation of the influence of out-of-round wheels on wheel-rail contact forces and vehicle/track responses are described. © 2009 Woodhead Publishing Limited.

T.X. Wu

Papers

A hybrid model for the noise generation due to railway wheel flats

The effects of local preload on the foundation stiffness and vertical vibration of railway track