Non-destructive Testing Base On Ultrasonic Imaging Of Array

The rapid development of modern industry have made the non-destructive testing ask forhigh-precision, high-resolution, high reliability. and have made this kind of technology be awhole process and all field technology for it has played a very inportant role in the aspects ofdesigning, developing, producting, using etc. A variety of high-precision, high-parameter,complex structural components are putting forward more strict requirements to thenon-destructive testing. and making this kind of technic fuse with modern informationtechnology and computer technology. and then making it develop into digital, visualization,and non-destructive evaluation.After the deep research of the latest development at home and abroad, this paper expoundedthe related theory and algorithm of array ultrasonic nondestructive testing systematically fromthe point of imaging. and put forward the designing thread of ultrasonic detector array, andthen gave the mathematical expressions of the detector’s field in the spread of solid. The maincontents involve the following:The article introduced the basic physical structure of ultrasonic imaging detection of arrayat the beginning, including the ultrasonic imaging system, the directivity fuction of detectorarray, the model of ultrasonic diffraction in the solid, the progress of the transceiver focus ofthe detector array.After that, the article made3-D simulation for the directivity fuction of detector array withMATLAB. and analysised the effecting factor to the directivity of detector array, includingthe quantity of the cell, the relationship between t emission frequency and gap, therelationship between the size and the gap etc. and put forward the designing methord ofdetector array.At last, the article proposed an improved algorithm based on the traditional multigaussianbeam superposition algorithm. and also compare it with Rayleigh integral algorithm. provedthat this improved algorithm based on non-integral can imitate the spread field of the phasedarray detector in the solid. So it can be used without immersion environment, and it’sapplicable scope can be widely extended.The innovation points of this paper innolves:1. Gave a new explaination to the near field Dead Zone of ultrasonic detecting. Deducedthe impact to the number of null point by the relationship between detector’s diameter and the emission wavelength, and gave the equation of null point’s number and position.2. Made3-D simulation for the directivity fuction of detector array with MATLAB. andanalysised the effecting factor to the directivity of detector array, and put forward thedesigning technique of detector array.3.Proposed an improved algorithm based on the traditional multi-gaussian beamsuperposition algorithm, gave the field equation and delay equation based on phased arraydetectors. And then could make this improved algorithm imitate the spread field of the phasedarray detector in the solid.