Effect of Temperature on Solid Ultrasonic Propagation Using Finite Element Method and Experiments

Abstract

Time of flight (TOF) is considered to be a sign of solid ultrasonic propagation. The more precise measurement of TOF is the better propagation of ultrasonic in solid we can get. Uncertainties associated with coupling fluids or positional offsets can be eliminated by permanently installed ultrasonic probes. However, the variations caused by temperature need to be considered during measurement of TOF, which makes it potentially possible to monitor the onset of material degradation such as stress modification. In this paper, firstly, the finite element models of ultrasonic propagation in aluminum and steel were respectively established under temperatures from 25°C to 200°C. An error of ultrasonic flight-time due to the change of the ultrasonic path caused by solid thermal expansion was corrected, which was implemented and its performance was compared with simulated and experimental measurements. The results show that the modified velocity equation can effectively reflect the effluence of temperature on ultrasonic flight-time and ultrasonic velocity up to 200°C. The TOF measurements maximum relative errors in aluminum and steel were respectively decreased to 0.4395% and 0.5204%.