Method for generating maximum-intensity ultrasonic surface wave based on phased array technology

Abstract

The invention discloses a maximum intensity ultrasonic surface wave generation method based on a phased array technology, which comprises the following steps that: (1) when an ultrasonic phased arrayinstrument performs linear scanning, the incident angle of longitudinal waves excited by an ultrasonic phased array probe in a phased array acoustic transmission wedge block is alpha, the longitudinalwaves can be converted into ultrasonic surface waves at the interface between the phased array acoustic transmission wedge block and a workpiece, and the ultrasonic surface waves are transmitted to the right side plane of the workpiece on the upper surface of the workpiece, and when the amplitude of the surface reflection waves of the right side plane of the workpiece is adjusted to 80% full screen, the gain value A at the moment is recorded; and (2) the incident angle alpha of the longitudinal waves in the phased array acoustic transmission wedge block is adjusted within a selection range through the ultrasonic phased array instrument, the method turns to the step (2), the minimum gain value A(min) when the amplitude of the surface reflection waves of the right side plane of the workpiece is 80% full screen is searched within the range, and at the moment, the ultrasonic surface wave generated by the system is taken as the maximum-intensity ultrasonic surface wave.

Description

technical field [0001] The invention belongs to the field of acoustic transducers, acoustic measurement and methods, and relates to a method for generating maximum-intensity ultrasonic surface waves based on phased array technology. Background technique [0002] When ultrasonic waves propagate on a semi-infinite solid medium and the thickness of the medium is greater than the wavelength, ultrasonic surface waves will be generated under certain conditions. The composite vibration track of solid surface particles produced by ultrasonic surface waves is an ellipse around its equilibrium position. The long axis of the ellipse is perpendicular to the wave propagation direction, and the short axis is parallel to the wave propagation direction. The size of the particle amplitude is related to the elasticity of the material and the penetration depth of the surface wave, and its vibration energy decreases rapidly as the depth increases. When the penetration depth of the ultrasonic s...

AI Technical Summary

Problems solved by technology

However, in the actual surface defect detection, it is impossible to quickly obtain multiple sound-transmitting wedges with different longitudinal wave incident angles

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