Technical Reports

Evaluation of Wheel/Rail Contact Mechanics: Concepts Report

  • 25
  • Jul
  • 2014
AUTHOR: Mehdi Ahmadian and Michael Craft
SUBJECT: Track, Tracks & Structures, Track/Train Interactions
KEYWORDS: Roller Rig, Wheel-Rail Contact Mechanics, Rail Vehicle Dynamics, Contact Patch Dynamics, Wheel Forces and Moments
ABSTRACT: A need exists for a new test rig design with advanced sensing technologies that will allow the railroad industry and regulatory agencies to better understand the wheel-rail contact dynamics and mechanics, especially as it pertains to high-speed rail. Both scaled and full-scale designs are being investigated. The use of scaled designs will make testing possible at much lower investment and complexity than is required for full-scale testing. However, a scaled rig eliminates the ability to directly test with fielded and standard (off-the-shelf) components. Irrespective of the scaling, the controlled laboratory environment will assist with obtaining data on the mechanics and dynamics of the creepage and creep forces within the contact ellipse under various conditions; this evaluation process is essential for better understanding the fundamentals of wheel-rail contact dynamics and more effective rail dynamics modeling. Therefore, we recommend developing a streamlined test rig of 1/4 to 1/5 full-scale with precise test control and sensory system that allows for accurate measurement of the wheel forces and moments that occur in conditions representative of actual field occurrences. The scaled test rig may serve as a steppingstone for future development of a full-size rig.
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