High Frequency Ultrasound Detection Model Research

Ultrasonic testing is one of the most important test methods in non-destructive testing fields. In the testing, it is always the aim of ultrasonic testing to obtain the information of flaw rapidly and accurately. As the key tools, ultrasonic system and transducer play important roles, and it is one of developing field in ultrasonic testing that the investigation of ultrasonic instruments and transducers. In this paper, firstly by studing the equivalent model of each component of ultrasonic transducer,establish the effective ultrasound transducer model. Based on equivalent circuit model, we constructed an ultrasonic transducer acoustoelectric conversion model as a whole.Transducer frequency response function was studied and the response characteristics under different excitations are calculated.Based on the the study of the transducer acoustic field model, the calculation model of circular plane transducer sound field is established. Based on the Rayleigh integral model and the Multi-Gauss sound beam medel,the transducer acoustic field is calculated analyticly. Then the straight probe acoustic field is simulated with analysis and comparison, analyzing the influence of transducer parameters on the acoustic field, at the same time gives a straight probe beam directivity function.The application of ultrasonic transducer is studied in terms of thickness measurement. Mainly in view of the metal film, different processing method is used for different thickness measurement data. This paper studies two different models in thickness measurement,and present how to choose the thickness measurement model. Analyze the transducer longitudinal measurement resolution.Finally, this article introduces the design principles of ultrasonic microscopic measurement system, introduces the hardware and software component of microscopic measurement system prototype, and the microscopic measuring lateral resolution is modeled. for frequency has carried on the qualitative analysis to the influence of the resolution In view of the frequency, the experiment has been carried on to botain the influence on the resolution qualitatively.