Monitoring of rail forces by using acoustic signature inspection

The build-up of internal rail forces causes track failures and these forces, when compressive, can cause track buckling. A technique suitable for field use is required to measure these forces. An acoustic technique based on the dependence of the rail's vibrational response to the magnitude of the axial force in the rail, is proposed here as a method for making such a measurement. A realistic two-layer continuous track model is used to predict the response as a function of the magnitude of the force. Considerations for the design of a system to measure rail forces in the field are discussed.