A Habibpour-Ledari - PhD student, Faculty of Aerospace Engineering, K. N. Toosi University of Technology, Tehran, Iran
F Honarvar - Professors, Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran

Time-of-Flight Diffraction technique (ToFD) is one of the advanced ultrasonic testing methods. ToFDtechnique has high accuracy in locating and sizing discontinuities. Despite the many benefits of ToFD, it suffers from anumber of shortcomings. One limitation is that the current ToFD technique is considered to be a two-dimensionalmethod which can only evaluate the defects in the cross-sectional plane of the specimen. The goal of this paper is todevelop a technique for locating and sizing of discontinuities in three-dimensional space. To this end, instead of using apair of transducers, a combination of multiple transmitting and receiving transducers is considered. The approach forlocating and sizing defects in a 3D space follows the methods used in radar and acoustic positioning systems. Noniterativetechniques are used for positioning a single source (defect) based on signals collected by several transducers.This method is tested on a specimen with artificially implanted defects and the three-dimensional location of the defectis found with very good accuracy.

Ultrasonic NDT, ToFD technique, Source positioning, Defect location and sizing