The Research On Three-dimensional Imaging Technology Of Array Ultrasonic Flaw Detection

In the field of industrial non-destructive testing,the three-dimensional imaging technology of ultrasonic flaw detection can visually represent the three-dimensional spatial characteristics of defects.This article combines ultrasonic phased array technology with three-dimensional visualization technology to carry out research on three-dimensional imaging technology of ultrasonic flaw detection.The main work and achievements are as follows:Firstly,the relevant theories of ultrasonic imaging,including the basic theory of ultrasonic propagation,the principle of ultrasonic flaw detection,the principle of ultrasonic phased array technology and its imaging characteristics are elaborated;based on the research of the ultrasonic phased array radiation sound field theory,the two-dimensional rectangular array probe is selected Data acquisition,giving the directivity function of the two-dimensional array probe,and analyzing the influence of probe parameters on the radiated sound field.Design a threedimensional spatial phased array ultrasonic focusing rule and scanning form based on a twodimensional rectangular array probe,and use Field II software to conduct defect detection simulation experiments and analyze the three-dimensional imaging results.Secondly,the ultrasound data processing and visualization algorithms are studied.Analyze the advantages of using orthogonal demodulation algorithm to extract the ultrasound echo envelope signal and experimentally verify the effectiveness of the algorithm.Derive a threedimensional linear interpolation formula for ultrasound data reconstruction.Consider the use of ray projection volume rendering algorithm for ultrasound data visualization based on the imaging effect.Based on the data acquisition,data processing and data visualization algorithms designed in this paper,the three-dimensional imaging of ultrasonic flaw detection of transverse hole defects and bolt line defects is carried out,and the experimental results are qualitatively and quantitatively analyzed.The experimental results show that the three-dimensional imaging technology can accurately display the internal defect distribution of the workpiece.Finally,fast ultrasound data visualization based on CUDA is realized to meet the user’s real-time interaction requirements.The GPU texture memory is used to accelerate the reconstruction of ultrasound data volume,and a ray projection volume rendering algorithm based on the CUDA programming model is implemented.At the same time,the algorithm is optimized by three methods: storage optimization of viewing angle conversion matrix,early termination of light and variable sampling step.The results show that the speed of ultrasound data volume reconstruction and volume rendering using the GPU parallel computing method is significantly improved compared with the traditional CPU serial computing method,and the visual frame rate reaches more than 20 fps.