A Method for Reconstructing Internal Temperature Distribution in Solid Structure

Abstract

In this paper, a method combining ultrasonic travel time measurement with inversion is proposed to reconstruct the solid temperature field. Based on the measured transient ultrasonic propagation time, the inverse problem of acoustic thermal coupling is solved directly, and the unknown equivalent heat flow is estimated. Then, the time and space distribution of the internal temperature field can be reconstructed accurately by calculating the corresponding heat conduction problems. Through the estimation of two typical heat flow function forms, the accuracy and influencing factors are simulated and analyzed. The feasibility and error of this method are analyzed through a transient verification experiment of a steel plate heated first and then cooled and a steady-state experiment in the literature. The results show that, compared with the previous methods, this method can predict the distribution of non-uniform temperature field more accurately and effectively. This method is expected to be an effective method for nondestructive testing of temperature distribution of solid structures.