| Welding technology is widely used in the petrochemical industry,pressure vessel,nuclear power and other mechanical industries.With the further development of industrial technology,more and more special-shaped structure welds appear.Ultrasonic phased array inspection technology relies on the advantages of flexible beam deflection and focusing,Applied to special-shaped weld inspection.Due to the complex internal structure of special welds,facing the problems of poor quality of the inspection map imaging and difficulties in identifying and locating defects,it has become the research focus to select the optimal inspection process parameters to improve the imaging resolution of the defect map.The process parameters of ultrasonic phased array detection were optimized.The specific research contents are as follows:(1)According to the structural characteristics of the block to be tested,combined with CIVA simulation software,design a three-dimensional model of the special-shaped weld test block.Based on the portable ultrasonic phased array detector produced by M2 M,an experimental platform was constructed to study and analyze the C-scan diagram and fan-scan diagram of simulation inspection and test inspection.Based on the length measurement principle of-6dB method,the length,size and position of the defect were quantified Analysis to determine the reliability of simulation modeling.(2)Simulation to study the influence of different detection process parameters on the focal width and depth of the sound beam at the focal point,with the number of wafers,probe frequency and focal length as independent variables,and the difference in peak and valley amplitude as the response amount to simulate the test block To study and analyze the influence of a single factor on the imaging resolution of the ultrasonic phased array detection map.It provides theoretical basis and data for the optimization of ultrasonic phased array detection parameters.(3)Combined with the simulated inspection data,based on Design Expert 10.04 software,a multi-parameter coupled statistical model was constructed,and a factorial test consisting of 12 sets of CIVA ultrasonic simulation inspection data was analyzed to analyze the significant ultrasonic phased array inspection that affected the defect imaging resolution The process parameters are analyzed to determine whether there are coupling effects on the process parameters.The Box-Behnken design method was used to obtain theternary quadratic regression equation.The model was analyzed for variance,combined with the response surface plot and contour plot of the effect of the detection process parameters on the peak and valley amplitude difference to further analyze the probe frequency and the number of wafers.3.Optimization of process parameters for focal length detection.(4)The simulation test of the optimized coupling detection process parameters is carried out.When the lateral resolution is the maximum,that is,the peak-to-valley amplitude difference reaches the maximum,the research results: the number of optimized wafers is finally determined to be 44,the probe frequency is 15 MHz,and the focal length is 40 mm.The difference between the maximum peak and the valley amplitude of the simulation results is 0.144 dB,which shows that the optimized ultrasonic phased array detection process parameters have the best imaging resolution.(5)Build an ultrasonic phased array detection test platform to conduct three sets of tests,and obtain three sets of different peak and valley amplitude differences according to the obtained ternary quadratic regression model.By comparing the A-scan images generated in the fan scan,comparing the peak and valley amplitude difference between the test and the fitted model,the rationality of the statistical model and the reliability of the optimized parameters are proved.The results of this paper provide some guidance for the further study of the imaging resolution of the abnormal weld defect map. |
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