Railway wheel web fatigue design diagram

Abstract

Fatigue design of the railway wheel web is carried out in compliance with the JRIS J 0405 standard. However, this standard does not specify any evaluation method considering the thermal stress on the wheel web owing to tread braking. The thermal stress in fatigue design should be evaluated as the average stress in the endurance limit diagrams. In addition, it is necessary to evaluate it considering the variations in the actual mass productions and the fatigue strength in the design of actual wheels. In this study, plane bending fatigue tests using the cut wheels were conducted, and various properties of the actual mass productions were measured to evaluate the variations in them statistically. These tests clarified the fatigue limits and the standard deviation at stress ratios of -1 and 0.7. It was found that a curve, which was a combination of σa － σT and σmax = σf diagrams, corresponded well to the test results. The equivalent standard deviation in the fatigue limit was obtained from the variations in the fatigue properties and the properties of the actual mass production wheels. The fatigue design curve of the wheel web, based on the proposed endurance limit diagram, was determined so that the fracture probability at all the stress ratios was less than 10-6 by using the equivalent standard deviation.

Keywords

• fatigue design
• railway wheel web
• tread brake
• endurance limit diagram
• fracture probability