Load Environment of Rail Joints – Phase I Effects of Track Parameters on Rail Joint Stresses and Crack Growth

The load environment of joint bars was assessed under a variety of loading and track conditions. Bending stresses, thermal stresses, and residual stresses were measured on commonly used joint bars. Crack growth rates from artificially induced cracks were also monitored. This study provides the relevant data and analysis results needed for developing more comprehensive models for joint bar failure, fatigue life, crack growth, and inspection interval optimization. The data provided will also help railroads to design more reliable and safer joint bar designs. Bending stresses in joint bars vary widely in local foundation and loading conditions. Stresses too low to cause fatigue damage and stresses large enough to cause joint bar breakage were measured. Thermal stresses in insulated joint bars are similar to those found in rail. Data also shows that once one joint bar of a standard joint is broken because of fatigue or manufacturing defect, the other joint bar carries all of the longitudinal and bending loads from the broken bar. This puts high stresses on the remaining bar, which sometimes breaks. This is consistent with the fact that in many cases both joint bars are found broken on inspection. The data also shows that thermal stresses can increase significantly because of maintenance operations, such as surfacing and under cutting.

• Record URL:
  https://www.fra.dot.gov/eLib/details/L04515#p1_z50_gD_lRT_y2013
• 
• Availability:
  • Find a library where document is available. Order URL: www.fra.dot.gov
• Corporate Authors:

  Transportation Technology Center, Incorporated

  55500 DOT Road
  Pueblo, CO  United States  81001

  Federal Railroad Administration

  Office of Research and Development, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Akhtar, Muhammad N
  • Davis, David D
• Publication Date: 2013-4

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 47p

Subject/Index Terms

• TRT Terms: Bending stress; Load tests; Rail joints; Stress cracking; Thermal stresses
• Subject Areas: Railroads; Vehicles and Equipment; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 01481512
• Record Type: Publication
• Report/Paper Numbers: DOT/FRA/ORD-13/24
• Contract Numbers: Funding Number: DTFR53-00-C-00012 Task Order 238
• Files: TRIS, ATRI, USDOT
• Created Date: May 17 2013 12:17PM