小直径棒材超声横波检测仿真分析

采用超声水浸聚焦斜入射方式进行小棒材表面、近表缺陷检测时,声波在水/棒和棒/缺陷界面会发生反射、折射、散射、衍射及波形转换等一系列物理变换。此时缺陷可检性对声波入射条件十分敏感,常出现由于检测条件设置不当而导致缺陷漏检、误检的情况。为解决这一问题,本文针对小棒材超声斜入射检测中的主要参数——入射角和水距,开展声场及缺陷声响应仿真,研究检测参数对不同部位缺陷检测能力的影响,并对仿真结果进行试验验证。通过研究得到了检测水距、入射角度对缺陷检测能力的影响,并得到最优检测条件。试验验证结果表明研究制定的检测方案可有效检测出表面、近表面裂纹缺陷。

Simulation and analysis for ultrasonic transverse wave testing of small diameter bar

ultrasonic immersion focusing test technology with Oblique incidence sound wave is used to detect the surface and near surface defects of small bars. A series of physical transformations, such as reflection, refraction, scattering, diffraction and waveform conversion, may occur. The detestability of defects is sensitive to the incident conditions of sound waves. Defects may be detected and evaluated by error because of the improper setting of detection conditions. Incident angle and water distance are the main parameters of ultrasonic oblique incidence testing of small bar. The acoustic field and defect acoustic response simulations are carried out by changing the values of the two main parameters. The influence of the defect detection ability in different parts is studied. The guidance scheme of testing small bar is given. At last,the simulation results are verified.