| The radiated sound field of traffic circle is analyzed in this paper. Founding the radiated sound field model and calculating the model analytic result, the ultrasonic pressure distribution in three-dimensional space is calculated , and its near field distribution.An analysis is made of pressure distribution of radiated sound field, and the pressure distribution on the axis is discussed under the near sound field .In addition, using ART II algorithm, based on the research of image reconstruction theory, an ultrasonic—CT (Computerized Tomography) program is made. By applying the program to analyze the data of ultrasonic wave propagation time about concrete testing models, CT images are performed, which reflect the variation of wave velocity in concrete testing models. The CT images, which can reflect the location and the range of the defect in concrete testing models.At last, the limitation of the ultrasonic — CT(Computerized Tomography) and its development direction are discussed. |
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