Stress monitoring using the change in velocity of Rayleigh waves

Abstract

This paper describes a novel technique for stress monitoring using Rayleigh waves. Nonlinearity within an Aluminium specimen generated as a result of applied stresses causes a change in the velocity of a Rayleigh wave due to the acoustoelastic effect. Measurement of the stress requires the second order (Lamé) and third order (Murnaghan) elastic constants, the latter of which is typically difficult to accurately measure due to their sensitivity to fatigue and residual stresses. Using the method presented, the Murnaghan constants are determined and the resultant stress predictions are compared to theoretically derived results with high accuracy.