A Computer Program for Determining the Effect of Design Variation on Service Stresses in Railroad Wheels

Two computer analyses have been prepared relating service stresses in railroad wheels to wheel shape and dimensions. One program computes the temperature distribution and stresses due to heat input by brake shoe friction at the wheel tread. The other computes stresses due to lateral, vertical, and tractional forces between the wheel and rail. Both programs have been validated for certain known conditions using theoretical solutions and are in agreement with available design and experimental stress data to the degree that differences in wheel geometry and loading conditions permit a comparison with experimental stress data. The next step contemplated is better experimental confirmation by computations for specific wheels and loadings for which test results are available and use of the programs to study trends resulting from, changes in wheel geometry and dimensions. This work is directed toward optimization of wheel design, and elucidation of the nature and specific effects of excessive service loads. This research program is being sponsored at General Electric by the manufacturers of wrought steel wheels, through the American Iron and Steel Institute, as a service to the American railroad industry.