The Research On Ultrasonic Phased Array Imaging Technology

Nowadays the ultrasonic phased array imaging detection technology has an increasingly wideapplication in the field of industrial non-destructive testing. By controlling the delay time of eachelement, the technology can change the location of the focus point and the direction of the beam andtherefore form combined phased beam, i.e., the imaging scanning line. With advantages of dynamicfocusing, high resolution, high SNR (signal noise ratio) and high sensitivity, among others, thetechnology has become a hot topic of NDT at home and abroad recent years.This paper mainly studies the related theories of ultrasonic phased array inspection, including theprinciple of the transducer array radiation, the method of the phased array beam control and the theoryof flaw imaging, etc. Simulation is done to research the sound field of one-dimension array transducer,in order to find out how different transducer parameters will influence on the sound beam focusing.Dynamic focusing of phased array is achieved, which offers a theoretical ground to the research andmanufacture of array transducer.The defect imaging model is simulated both with single-point focusing and dynamic focusing of thesound beam. The sub array synthesizing is achieved using synthetic aperture technique. In this way,the detection efficiency of the system and the contrast ratio of defect imaging are improved.A16-channel ultrasonic phased array system is designed to send and receive ultrasonic sound. Thesoftware of phased array is dong by the program language of matlab. The defect imaging is done withprocessing of received signals. Experiment results show that dynamic focusing technology has ahigher imaging resolution and contrast than non-dynamic focusing technology.