入射偏角对管件壁厚超声测量影响研究

Influence of Incident Deflection Angle on Ultrasonic Measurement of Pipe Fitting Wall Thickness

针对超声测厚过程中,探头受被测面形状复杂影响,致使声束中心线与被测表面测点处法矢之间不可避免地存在偏角导致较大测厚误差的问题,本文研究了入射偏角对管件壁厚超声测量的影响。采用多物理场有限元仿真软件声-结构耦合模块分析了在0°~2°范围内入射偏角对超声测厚声场分布的影响机制,得出了声压随偏角的变化规律,量化了不同偏角下测厚误差的数值大小,建立了入射偏角引起的测厚误差补偿模型。最后通过量块和管件的测厚实验验证了方法的可行性。结果表明随着入射偏角的增大,测量误差逐渐增大,通过对偏角引起的测厚误差进行补偿,在0°~0.5°范围内补偿后的管件测量误差最多可减小53%。

In the process of ultrasonic thickness measurement,due to the complicated shape of the measured surface,the probe inevitably has a deflection Angle between the center line of the acoustic beam and the normal vector at the measuring point of the measured surface,which leads to a large thickness measurement error.This paper studies the influence of the incident deflection Angle on the ultrasonic measurement of pipe fitting wall thickness.The sound-structure coupling module of multi-physical finite element simulation software was used to analyze the influence mechanism of incident deflection Angle on ultrasonic thickness measurement field distribution in the range of 0°~2°,and the variation rule of sound pressure with deflection Angle was obtained.The numerical size of thickness measurement error under different deflection Angle was quantified,and the thickness measurement error compensation model caused by incident deflection Angle was established.Finally,the feasibility of the method is verified by measuring the thickness of the measuring block and pipe fitting.The results show that the measuring error increases gradually with the increase of incident deflection Angle.By compensating the thickness error caused by the deflection Angle,the measuring error of pipe fitting can be reduced by up to 53%in the range of 0°~0.5°.