Kraskovskiy O. Ultrasonic phased arrays with high resolution of systems for nondestructive testing of metal products

The thesis is a research work for obtaining the candidate of technical sciences degree on speciality 05.11.13 - devices and methods of testing and determination of materials composition. - National Technical University of Ukraine "Kyiv Polytechnic Institute" - Kyiv, 2013. Dissertation is devoted to design of phased array (PA) of piezoelectric transducers (PT) for ultrasonic information-measurement system for nondestructive testing of metal products. New methods of suppressing spurious modes in PT of real linear PA are developed and experimentally investigated. Based on analytical-experimental method, adequate mathematical models of linear PA spatial-temporal characteristics that consider complex influence of main spurious effects on transmitting and receiving impulse signals are constructed. Based on proposed mathematical models, technique and software for calculating linear PA spatial-temporal characteristics with impact of different spurious effects are developed. Methods and measuring systems for experimental research of linear PA parameters and characteristics are designed. Samples of linear PA are constructed using proposed methods of suppressing spurious modes in PT of PA. Experimental investigations of linear PA are performed within ultrasonic information-measurement system for nondestructive testing of metal products.