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Rail Safety IDEA Project 15 [Completed (IDEA)]
Determination of the Longitudinal Stress in Rails
| Project Data |
| Staff Responsibility: |
Harvey Berlin |
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The objective of this project was 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.
Investigators at the Texas Transportation Institute, which is an Association of American Railroads (AAR) Affiliated Laboratory, developed a methodology to determine the RNT in a nondestructive and non-contact manner. This gives 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 method and its application on rails are that it could reduce rail buckling due to temperature-induced stresses, which could decrease the number of train derailments.
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