激光层析法空耦超声换能器轴向声场测量研究

Assessment of Axial Sound Field in Air-Coupled Ultrasonic Transducers via Laser Tomography

空气耦合(简称“空耦”)超声换能器具有非接触、非侵入、完全无损等特点,在航空航天复合材料以及其他孔隙类材料的无损检测领域具有广阔的应用前景。开展空耦超声换能器的轴向声场重建研究,其所包含的近场长度、指向性等轴向声场特性参数,决定着换能器在无损检测中的分辨率、抗干扰及定位精度等性能。激光层析法在声场重建中具有高空间分辨力、宽频带范围和声场非侵入等优点,然而该方法目前主要被用于径向声场表征,轴向声场表征的理论和实验研究较少且不完善。从理论、仿真和实验的角度对空耦超声换能器的轴向声场分布展开研究,实验与仿真结果取得较好的一致性。同时与传声器的轴向声场测量结果进行比较,验证了激光层析法进行空耦换能器轴向声场重建的可靠性。研究结果对于空耦换能器轴向声场的测量、空耦超声换能器的设计和校准具有重要价值。

Air-coupled ultrasonic transducers,renowned for their non-contact,non-invasive,and completely nondestructive properties,have a wide range of applications in non-destructive testing,particularly in aerospace composite materials and porous materials.The study of axial sound field reconstruction in these transducers is critical as parameters such as near-field length and directionality significantly impact resolution,anti-interference capability,and positioning accuracy in non-destructive testing applications.Laser tomography,with its advantages of high spatial resolution,broad frequency range,and non-invasive sound field mapping,presents a promising approach for sound field reconstruction.However,its application has been predominantly focused on radial sound field characterization,with limited and incomplete exploration in the axial sound field domain.This research conducts a comprehensive investigation into the axial sound field distribution of air-coupled ultrasonic transducers from theoretical,simulation,and experimental perspectives using laser tomography.The study reveals a high degree of consistency between experimental results and simulations.Additionally,the research contrasts these findings with axial sound field measurements obtained via traditional microphone methods,validating the efficacy of laser tomography for accurate reconstruction of the axial sound field in air-coupled transducers.These results are invaluable for enhancing the measurement accuracy of the axial sound field in air-coupled transducers and contribute significantly to their design and calibration.