Ultrasonic transducer sound field measuring method based on dynamic photoelastic method

Abstract

The invention relates to an ultrasonic transducer sound field measuring method based on a dynamic photoelastic method. The measuring method includes the following steps that an ultrasonic transducer generates a radiation sound field in a sample, and a light source emits to generate light pulses; stress intensity, a distributed transient sound field image and a distributed steady sound field image of the radiation sound field are collected; graying processing is performed on the transient sound field image to obtain a grayed transient sound field image; the grayed transient sound field image is processed through calculation, and the wave length and center frequency of the ultrasonic transducer sound field are obtained; graying processing is performed on the steady sound field image to obtain a grayed steady sound field image; the grayed steady sound field image is processed, and the near field distance, the directivity and the spread angle of the ultrasonic transducer sound field are obtained. By the adoption of the dynamic photoelastic method, the ultrasonic transducer sound field measuring method can rapidly and accurately obtain the information of the ultrasonic transducer sound field by using processing of the transient sound field image and the steady sound field image.

Description

technical field [0001] The invention relates to a method for measuring the sound field of an ultrasonic transducer, in particular to a method for measuring the sound field of an ultrasonic transducer based on a dynamic photoelastic method. Background technique [0002] An ultrasonic transducer is a device that converts other forms of energy into sound energy. Among the ultrasonic generation methods, piezoelectric transducers are the most widely used. The test of ultrasonic transducer sound field plays a fundamental role in ultrasonic detection. There are two traditional methods for testing the sound field of ultrasonic transducers: one is the water immersion method; the other is the test block method. [0003] The water immersion method generally fixes a small steel ball with a diameter of 1mm in water, changes the inclination angle of the ultrasonic transducer and the distance from the steel ball, and gradually measures the ultrasonic transducer’s vibration amplitude by m...

AI Technical Summary

Problems solved by technology

Since water can only propagate longitudinal waves, not transverse waves, the water immersion method can only measure the sound field of longitudinal wave transducers

Moreover, the sound velocity and acoustic impedance of water are very different from the metal materials commonly used in industry. The sound field measured by the water immersion method cannot reflect the real sound field in the metal, and its application is limited.

[0004] The test block method needs to prepare a series of semicircular test blocks with different diameters, the uniformity of the test blocks is difficult to guarantee, and the different diffusion angles of each test block must be scanned once, which is more cumbersome to operate

In particular, the shear wave transducer needs to be pasted on the surface of the test block. Every time a measurement point is changed, the receiving transducer must be pasted again. The scanning process is more cumbersome and the consistency is difficult to guarantee.

[0005] Therefore, the sound field characteristics measured by the traditional ultrasonic transducer sound field test method are affected by the characteristics of the receiving transducer and the receiving circuit, and are not the actual sound field

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