【摘要】 超声检测是比较常用的金属棒材无损检测技术,为提高超声回波信号的强度,提高信噪比,通常采用聚焦超声探头进行检测。但由于棒材表面为曲面,原本的聚焦声束被折射后焦点位置可能会发生变化。本文从理论上研究不同棒材表面曲率半径对超声声束的影响,然后通过仿真进行验证。研究发现,同一声束焦点位置和水声程、棒材半径以及检测的材料都有关系,可以作为参考来布置聚焦超声探头的位置,以提高检测的准确度。最后通过实验证明,考虑棒材表面曲率的情况下能显著提高缺陷回波信号强度和信噪比。更多还原

【Abstract】 Ultrasonic testing is a common non-destructive testing technology for mental bars.Focused probe is often used to increase the strength of ultrasonic echo signal and the signal-to-noise ratio.However, the focus position of the focused sound beam may change because of the curved surface of the bar.Therefore, the influence on the sound beam of different bar surface was studied, and the simulation was operated to verify the theory.The study found that the focus position of the sound beam is related to the waterdistance, the radius and the material of the bar to be tested, which can be used as a reference to arrange the position of the focused probe to improve the accuracy of the detection. Finally, the experiment proved the strength of the defect echo signal and the signal-to-noise ratio can be significantly improved by taking the curved surface into consideration.更多还原