Two-dimensional Array Guided Wave Focusing Method And Nondestructive Testing System Research

Curved surface thin plate parts are largely applied in key parts of significant devices. Because of terrible working condition, these parts are easy to form various types of defects. So this kind of parts must be detected and monitored strictly by ultrasonic nondestructive testing(NDT) methods to ensure normal work. Faced with the curved surface detection problem, this paper put forward new ideas of array guided wave to detect curved parts surface defects by using flexible array transducer, which has good coupling with curved surface.Guided wave has multiple modes and dispersion propertity. Based on the principle of guided wave detection, the paper has made a research on array transducer guided wave mode control. And then the frequency control and phase control theory has been presented to control the guided wave mode. To improve the detection efficiency, we have designed the flexible two-dimensional array transducer. Based on mode control and phase control theory, we put forward the algorithm of two-dimensional array guided wave double phased focusing. And we applied the algorithm to the theory of two-dimensional array of guided wave imaging.According to flexible two-dimensional array transducer design and algorithm research, two-dimensional array nondestructive testing system was designed. And we construct twodimensional array nondestructive testing system by hardware selection and detailed software modular design. Then by using the nondestructive testing system, the verification and testing experiments are designed on reference block round holes, crack in aluminum plate and blade defects. The experimental results show that the function of the system and the theory of algorithm is correct, and we can use the system to detect the defects of different parts by real time B scan imaging.Through the experiment, the two-dimensional array nondestructive detection system can be used in guided wave and Rayleigh wave detect, and the core is to achieve the real-time B scan detection of curved surface defect, users will be convenient to identify defect location through system real-time image to improve the detection efficiency and reliability.