Sen Novonil, Kundu Tribikram
Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA.
Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA; Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, AZ 85721, USA.
Ultrasonics. 2018 Jul;87:20-32. doi: 10.1016/j.ultras.2018.01.011. Epub 2018 Jan 31.
Estimating the location of an acoustic source in a structure is an important step towards passive structural health monitoring. Techniques for localizing an acoustic source in isotropic structures are well developed in the literature. Development of similar techniques for anisotropic structures, however, has gained attention only in the recent years and has a scope of further improvement. Most of the existing techniques for anisotropic structures either assume a straight line wave propagation path between the source and an ultrasonic sensor or require the material properties to be known. This study considers different shapes of the wave front generated during an acoustic event and develops a methodology to localize the acoustic source in an anisotropic plate from those wave front shapes. An elliptical wave front shape-based technique was developed first, followed by the development of a parametric curve-based technique for non-elliptical wave front shapes. The source coordinates are obtained by minimizing an objective function. The proposed methodology does not assume a straight line wave propagation path and can predict the source location without any knowledge of the elastic properties of the material. A numerical study presented here illustrates how the proposed methodology can accurately estimate the source coordinates.
估计结构中声源的位置是迈向被动结构健康监测的重要一步。文献中已经很好地开发了在各向同性结构中定位声源的技术。然而，针对各向异性结构的类似技术的开发只是近年来才受到关注，并且有进一步改进的空间。大多数现有的各向异性结构技术要么假设声源与超声传感器之间存在直线波传播路径，要么要求已知材料特性。本研究考虑了声学事件期间产生的不同波前形状，并开发了一种从这些波前形状中定位各向异性板中声源的方法。首先开发了基于椭圆波前形状的技术，随后开发了用于非椭圆波前形状的基于参数曲线的技术。通过最小化目标函数来获得源坐标。所提出的方法不假设直线波传播路径，并且无需任何材料弹性特性的知识即可预测源位置。此处给出的数值研究说明了所提出的方法如何能够准确估计源坐标。
