The application of contact mechanics to rail profile design and rail grinding

While many railway engineers are exploring the benefits of the latest lubrication technologies, bogie types and metallurgies, the wheel/rail (w/r) contact mechanics are often overlooked or poorly controlled. But the geometry of the w/r contact permeates every facet of the w/r interaction, having profound effects on wear, fatigue, corrugation, stability and derailment potential. A pummelling model is being developed at the NRC Centre for Surface Transportation Technology to quantify the performance of rail profiles when loaded by a large number of measured new and worn wheels. Typical results are shown for the RE136-10″, UIC60 and RE141 rail profiles. Contact mechanics principles are further applied in a discussion of several aspects of rail grinding, including surface roughness, facet width and rail grinding interval.