Computer aided modeling of ultrasonic surface waves propagation in materials with gradient of properties

Abstract

The present work deals with modeling of generating, propagation and receiving of theRayleigh impulse in material with gradient of properties. The spectrum of an ultrasonic signal, having passed through a material, is determined by the spectrum of the exciting electrical signal, frequency characteristics of the transmitting and receiving transducers and by material characteristics. The dispersion of theRayleigh wave is obtained as a result of the simulation done by spectral decomposition of impulse and processing components considering wave penetration and wave velocity changes caused by gradient of mechanical characteristics. Simulated ultrasonic waveforms allow evaluation of the time delay effect induced by stress gradient. Application of ultrasonic wave for stress analyses is possible on the basis of spectral analysis and phase comparisons of ultrasonic impulse.