Simultaneous measurement of the velocity of an ultrasonic shear wave and the thickness of a test object with plane-parallel boundaries using two antenna arrays

Abstract

Methods for the determination of the unknown velocity of the propagation of shear US waves and the unknown thickness of a test object were considered. Two antenna arrays working in the double-scanning mode, where echo signals are recorded, which were emitted and received by all pairs of antenna-array elements, were suggested. Antenna arrays on prisms were mounted on the test-object surface towards each other. An algorithm for the treatment of measured echo signals was designed using a method that is similar to the least-squares method. The use of the algorithm enables one to simultaneously determine the sound velocity and thickness of a test object with plane-parallel boundaries with an exactness greater than 0.5%. In this article, the factors were studied that affect the exactness of measurements and methods of their elimination or minimization. The results of numerical experiments and the use of the method on three samples relative to measurements using an IN-5101A instrument are given.