Advanced Rail Tension Monitor (RTM) for In-Place Stress Measurement and Analysis

Maintaining straightness of continuously welded high speed DoD track rails is critical to the facility's mission, since test vehicles, often traversing the track at up to Mach 10, can experience dangerous dynamic loading due to track irregularities. Although facilities are constructed with adequate pretension to reduce undesirable effects of irregularities and thermal expansion/contraction over wide temerature ranges, tracks breads often preclude the maintenanct of pretension. An advanced sensing system to monitor rail stress, and software tools to provide supporting analytical capability would be highly beneficial In the U.S. transportation sector, a similar requirement exists to monitor rail tension in welded rails. Increasing traffic, speed, and rail loads make the requirement increasingly important. An advanced analysis and test program for this applicaiton is proposed for side-by-side testing of the two most advanced technologies for non-destructive rail monitoring: electro magnetic acoustic transduction (EMAT) and non-linear harmonic (NLH) magnetic hysteresis. The project will experimentally compare the technologies against the requirements of a DoD test track, determine the best approach, develop a conceptual system design, and fabricate the test prototype hardware. Supporting tools to analyze rail stress response to temperature will also be developed in working prototype form.