Ultrasonic transmission measurements in the characterization of viscoelasticity utilizing polymeric waveguides
Ultrasonic transmission measurements in the characterization of viscoelasticity utilizing polymeric waveguides
复制标题
利用聚合物波导进行粘弹性表征的超声波传输测量
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
B. Henning
中科院分区：
文献类型：
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作者：
Fabian Bause;J. Rautenberg;N. Feldmann;M. Webersen;L. Claes;H. Gravenkamp;B. Henning
对于声波在（测量）系统中的传播及其设计的数值模拟，可靠的材料模型和材料参数的使用是一个核心问题。特别是在聚合物中，声学材料参数不能根据准静态测量参数进行评估，正如制造商在数据表中规定的那样。在这项工作中，提出了一种测量方法，用于定量给定聚合物材料样品，复值和频率相关的材料模型。介绍了一种新的三维粘弹性建模方法。考虑到被测聚合物的高阻尼特性，材料样品被设计为空心圆柱形波导，并提供轴对称结构，以获得良好的波导建模性能和实验中较小的耦合面积所产生的可重复性耦合条件。在样品的平行面之间进行超声波透射测量。为了考虑材料特性的频率依赖性，使用了五种不同的换能器对，其中心频率从750 kHz上升到2.5 MHz。通过样品后，接收到的五个信号中的每一个都包含在反过程中确定的材料参数的信息。通过创新的基于正演sbfem的整个测量系统模拟与实验确定的测量数据的迭代比较，实现了反问题的求解。对于给定的反问题解，计算每个确定的材料参数的测量不确定度的估计值。此外，本文还提出了一种基于激光声激励板状试样兰姆模的第二种测量装置。使用这种设置，可以在具有不同几何形状但由相同材料制成的样品上验证所识别的材料特性。
For the numerical simulation of acoustic wave propagation in (measurement) systems and their design, the use of reliable material models and material parameters is a central issue. Especially in polymers, acoustic material parameters cannot be evaluated based on quasistatically measured parameters, as are specified in data sheets by the manufacturers. In this work, a measurement method is presented which quantifies, for a given polymeric material sample, a complex-valued and frequency-dependent material model. A novel three-dimensional approach for modeling viscoelasticity is introduced. The material samples are designed as hollow cylindrical waveguides to account for the high damping characteristics of the polymers under test and to provide an axisymmetric structure for good performance of waveguide modeling and reproducible coupling conditions arising from the smaller coupling area in the experiment. Ultrasonic transmission measurements are carried out between the parallel faces of the sample. To account for the frequency dependency of the material properties, five different transducer pairs with ascending central frequency from 750 kHz to 2.5 MHz are used. After passing through the sample, each of the five received signals contains information on the material parameters which are determined in an inverse procedure. The solution of the inverse problem is carried out by iterative comparison of an innovative forward SBFEM-based simulations of the entire measurement system with the experimentally determined measurement data. For a given solution of the inverse problem, an estimate of the measurement uncertainty of each identified material parameter is calculated. Moreover, a second measurement setup, based on laser-acoustic excitation of Lamb modes in plate-shaped specimens, is presented. Using this setup, the identified material properties can be verified on samples with a varied geometry, but made from the same material.
影响因子：
2.4
作者：
Bause, Fabian;Gravenkamp, Hauke;Henning, Bernd
通讯作者：
Henning, Bernd