| Analytical methods were employed to investigate the various stresses acting upon railroad rails in typical mainline freight service in North America. Bending stress and deflection of the rail in the vertical direction and contact stress all due to direct wheel loads of cars were studied for a range of typical freight car capacities. Two computer programs were written for obtaining bending stress and deflections as well as contact stress. The results were compared to data found in the literature. In general, bending stress does not play a significant role in the design of railroad rails as compared to vertical deflections and more importantly contact stress. Analytical results show for increasing levels of loading that contact stress exceeds threshold values for standard carbon railroad rall. However, these stresses can be decreased by altering the contact geometry of wheel on rail. |
