Determination of the Longitudinal Stress in Rails

The objective of this project is to determine the longitudinal stress in rails, in order to reduce rail buckling due to temperature-induced stresses. Continuous welded rails (CWR) are typically long members which are susceptible to failure caused by temperature changes. Such rail temperature changes can cause considerable disruption to the rail network and, in the worst case, cause freight or passenger train derailment. An important parameter in analysis of temperature induced stresses is the rail neutral temperature (RNT) defined as that rail temperature at which the net longitudinal force in the rail is zero. The objective of this project is to determine the longitudinal stress in rails using the polarization of Rayleigh surface waves, to reduce buckling and fracture. In the final configuration, the experimental procedure will use a Nd:YAG pulse laser (Nd:YAG = neodymium-doped yttrium aluminum garnet) to generate ultrasonic waves in a rail and a laser Doppler vibrometer to measure both the in-plane and out-of-plane velocity components of a Rayleigh wave as a function of applied stress. By measuring the rail temperature, it is possible to identify the RNT. Investigators at the Texas Transportation Institute, which is an Association of American Railroads (AAR) Affiliated Laboratory, will work together to develop a methodology to determine the RNT in a nondestructive and non-contact manner. This would then give the railroads the opportunity to check their rail system and/or to correct the installation of the rails by installing the entire track system at the RNT. The potential safety benefits of this research and its application on rails are that rails will no longer buckle due to temperature-induced stresses, which would decrease the frequency of train derailments.


  • English


  • Status: Completed
  • Contract Numbers:

    IDEA Project 15

  • Sponsor Organizations:

    Safety Innovations Deserving Exploratory Analysis (IDEA)

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Berlin, Harvey

  • Start Date: 20091027
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 24024

Subject/Index Terms

Filing Info

  • Accession Number: 01545252
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: IDEA Project 15
  • Files: TRB, RiP
  • Created Date: Nov 26 2014 1:00AM