Abstract
Ultrasonic methods are being developed for sensing and control of high temperature material processes such as welding and solidification. One of the problems in these methods is the distortion of the sound field caused by the change in material properties due to temperature gradients. This paper describes a ray-tracing method for calculating the effects of temperature on ultrasonic propagation in such systems. In the ray-tracing method, the material is conceptually divided into a number of plane layers. The refraction at each layer boundary is calculated from Snell's law using the sound speeds determined from the temperatures of the adjacent layers. The time required for an ultrasonic pulse to traverse each layer is also calculated, allowing the determination of the total time along a particular path. The method is applied to calculating the time of arrival of echoes from various interfaces around a molten weld pool.
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Johnson, J.A., Carlson, N.M. & Lott, L.A. Ultrasonic wave propagation in temperature gradients. J Nondestruct Eval 6, 147–157 (1987). https://doi.org/10.1007/BF00568010
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DOI: https://doi.org/10.1007/BF00568010