School of Mechanical & Mining Engineering

Our current research is principally concerned with corrugations (dynamic wear), wheel squeel (fluid/structural noise) and squats (fatigue) restricting productivity and increasing maintenance costs in both industries. Rail corrugation research has recently resulted in the successful field implementation of a novel corrugation control prototype to minimize its growth. The group also conducts research on the modelling and design of advanced locomotive traction/creep controllers.

Research topics include:

  • Dynamic modelling, analysis and simulation
  • Rail Corrugation Prediction, Measurement and Control
  • Railway Noise & Wheel Squeal Prediction
  • Rail Squat Defect Prediction and Prevention
  • Locomotive traction dynamics and control model

Associated Research Centres and Groups

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Staff

Associate Professor Paul Meehan
Dr Bill Daniel
Dr Sheng Liu

Publications

Please click here to see A/Prof. Paul Meehan’s publications.

Contact Details

Please direct all enquiries to Prof Paul Meehan.

Current Research

New Alternating Current (AC) traction motor and control technology boasts increases in torque capacity over traditional Direct Current (DC) motors of 100-200%. They however require precision traction control to achieve steady performance close to the adhesion limit i.e. from 30% to 46%. As the rail industry has replaced a significant number of DC locomotives with modern AC locomotives owing to the economic benefits brought by higher torque capacity and lower maintenance cost of AC locomotives, there is discussion as to what effect this has on the wheel-rail contact under dynamic conditions.

The traction control behaviour of a locomotive and its dynamic impact on the rail tracks has not been investigated deeply in respect to transient and unstable fluctuations due to natural perturbations in friction/lubrication, wheel/rail profiles, track curvature, vehicle/track dynamics, wheel/track imperfections etc. Such transient traction behaviour is likely to be more significant to dynamic traction performance and track degradation (i.e. squat/corrugation formation etc.) than steady state behaviour. In order to study this, the vehicle/track dynamics, contact mechanics and traction and creep control behaviour of modern AC locomotive drives needs to be integrated and assessed as a total dynamic feedback interactive system. The aim of this research is to address these aspects to model and improve locomotive traction behaviour.

Research Facilities

Two-disc test-rig

The two-disc test-rig laboratory facility is our group is used to simulate rotational contact situations, such as rail-wheel contact. It consists of two steel disks of differing radii in rolling contact. The rolling radii of the upper wheel and lower wheel are 0.085 and 0.213m respectively and the transverse radius of curvature of the contacting surfaces are 0.04m and 0.30m for the wheel and rail disks. These values have been chosen to achieve similar stress conditions to the actual rail-wheel contact. The material of the wheel and lower disk is cast steel of chemical composition similar to the wheel/rail steels. On this rig, two discs of different diameters are driven by two motors, with controlled torque and speed to achieve a designed range of creep rate and traction coefficient conditions. Various of parameters are monitored during the test including torques on different axles, normal and lateral force (out-of-plain), the attack angle, profile of the disks, noise level, temperature, etc.