An investigation of the effects of axle spacing on the rail bending stress behavior

• Author / Creator

  Zhang,Lihua

• Under heavy and frequent train loads, large stresses can develop in the rail, of which the bending stress is an important portion. Bending stress may cause fatigue defects to grow and also result in rail breaks, which is the dominant failure mode according to the records of derailments caused by rail issues reported by the Transportation Safety Board of Canada. In this study, the rail bending stresses under different track and loading conditions when the axle spacing between adjacent railcars varies were investigated. Finite element models of different complexities were established using ABAQUS. The Winkler model was also used in the investigation for comparison and reference. Three levels of track modulus, which are 13.79 MPa, 27.58 MPa, and 41.37 MPa were studied, representing soft, medium and stiff track conditions respectively. Two rail sections, the 115 RE rail and the 136 RE rail, were used, which are common rail sections in North American freight railways. Location effects of wheel loads on the rail bending stress behavior when the axle spacing varies were also examined. It is demonstrated that when wheel loads were applied at the middle of the rail head surface, under each track modulus and for each rail section, the maximum bending stress at the rail head generally follows a pattern of first increasing and then decreasing when the axle spacing increases, while the maximum bending stress at the rail base fluctuates in a small variation range and does not show a clear pattern. This thesis provides useful guidance in the aspect of studying the effects of axle spacing on the rail bending stress behavior. At the end of the thesis, limitations of current work, recommendations, and future work were also addressed.

• Subjects / Keywords

  • Axle spacing
  • Rail bending stress

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R32B8VH4Z

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.