The ultrasonic oblique incidence method of fold waveguide bar
Waveguide bar technology has proven to be the most promising method for high-temperature ultrasonic inspection,playing an important role in ensuring the safe operation of pressure-bearing equipment and other aspects.Existing waveguide transducers are often used to monitor the corrosion process of wall thickness online due to the direct-entry emission of acoustic waves,which makes it difficult to effectively detect defects in the specified direction.To solve this problem,this paper proposes a waveguide bar with a bending structure based on the Snell theorem and the dispersion characteristics of guided waves to realize ultrasonic oblique incidence.The propagation characteristics of the horizontal shear wave in the fold waveguide bar are first analyzed,and the influences of the thickness and bending angle of the bar on the propagation of the acoustic wave in the bar are discussed.In addition,the directivity of the acoustic beam in the semi-infinite space of the fold waveguide bar is further investigated.Finally,the application value of waveguide ultrasonic oblique incidence is demonstrated by a pair of fold waveguide bars for online detection of structural internal defects.These results provide a solid theoretical basis for the online monitoring of waveguide ultrasound based on the oblique incidence technique.
万方数据
维普
