Elastic and Acoustoelastic Properties of Railroad Rail
Is Version Of
Begun in 1973, the Review of Progress in Quantitative Nondestructive Evaluation (QNDE) is the premier international NDE meeting designed to provide an interface between research and early engineering through the presentation of current ideas and results focused on facilitating a rapid transfer to engineering development.
This site provides free, public access to papers presented at the annual QNDE conference between 1983 and 1999, and abstracts for papers presented at the conference since 2001.
The measurement of thermally induced longitudinal forces in railroad rail is an important element in the control of train damage due to rail buckling or other modes of track failure. Acoustoelastic techniques, whereby stresses are inferred from small shifts in the ultrasonic velocity, are attractive because they can sample the stresses on the interior of the rail and because relatively simple instrumentation can be utilized . The effectiveness of acoustoelastic techniques, however, is limited by the degree to which other sources of velocity shifts are present, generally associated with rail-to-rail variations in microstructure. Figure 1 illustrates the problem. Stress is inferred from the shift in velocity from its stress free value, based on a proportionality constant known as the acoustoelastic constant. Errors in the values of either the stress free velocity or the acoustoelastic constant can lead to errors in the predicted stress.