Inhomogeneity reconstructions in tendon ducts via boundary integral equations
Inhomogeneity reconstructions in tendon ducts via boundary integral equations
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DOI：
10.1016/j.ndteint.2014.08.007
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发表时间：
2014-12-01
影响因子：
4.2
通讯作者：
Weiland, Thomas
中科院分区：
文献类型：
--
作者：
Yaman, Fatih;Weiland, Thomas
在这项研究中，作为一种替代以前提出的调查，牛顿型的数值算法，提出了一个肌腱管道内的空气空隙的位置和形状，并确定聚集在混凝土柱中的金属棒。模拟结构由四个声源以固定频率照射，使得在近场区域中在128个点处测量散射场。根据物理问题的性质，采用Dirichlet边界条件模拟空气腔，并假设金属物体的透射条件。此外，导电的边界条件，建议一个更现实的代表性的不均匀性生锈的金属皮肤的管道。势方法用于推导边界积分方程。通过Tikhonov正则化建立了病态方程的适当处理。所提出的反演算法的适用性进行了测试与现实的参数为不同的情况下，使用嘈杂的散射场数据和准确的数值结果，在10 kHz的未知的物理特性的管道的皮肤。(C)2014爱思唯尔有限公司版权所有。
In this study, as an alternative to the formerly presented investigations, Newton-type numerical algorithms are proposed to find location and shape of an air void inside of a tendon duct and to identify gathered metallic bars in a concrete column. The simulated structures are illuminated by four acoustic sources at a fixed frequency such that the scattered field is measured in a near-field region at 128 points. According to the nature of physical problems, the Dirichlet boundary condition is employed to model air-filled cavities and transmission conditions are assumed for metallic objects. Additionally, conductive boundary conditions are suggested for a more realistic representation of the inhomogeneities for the rusty metallic skin of the duct. Potential approaches are used to derive boundary integral equations. The proper treatment of the ill-conditioned equations is established via Tikhonov regularization. Applicability of the proposed inversion algorithms is tested with realistic parameters for different scenarios using noisy scattered field data and accurate numerical results are presented at 10 kHz for the unknown physical properties of the duct's skin. (C) 2014 Elsevier Ltd. All rights reserved.