Wave Propagation and Signal Processing (WPSP), Department of Physics, KU Leuven-Campus Kulak, 8500 Kortrijk, Belgium.
Mechanics of Materials and Structures (MMS), Department of Materials, Textiles and Chemical Engineering, Ghent University, Technologiepark 46, 9052 Ghent, Belgium.
Sensors (Basel). 2022 Jul 15;22(14):5314. doi: 10.3390/s22145314.
Scanning laser Doppler vibrometry is a widely adopted method to measure the full-field out-of-plane vibrational response of materials in view of detecting defects or estimating stiffness parameters. Recent technological developments have led to performant 3D scanning laser Doppler vibrometers, which give access to both out-of-plane and in-plane vibrational velocity components. In the present study, the effect of using (i) the in-plane component; (ii) the out-of-plane component; and (iii) both the in-plane and out-of-plane components of the recorded vibration velocity on the inverse determination of the stiffness parameters is studied. Input data were gathered from a series of numerical simulations using a finite element model (COMSOL), as well as from broadband experimental measurements by means of a 3D infrared scanning laser Doppler vibrometer. Various materials were studied, including carbon epoxy composite and wood materials. The full-field vibrational velocity response is converted to the frequency-wavenumber domain by means of Fourier transform, from which complex wavenumbers are extracted using the matrix pencil decomposition method. To infer the orthotropic elastic stiffness tensor, an inversion procedure is developed by coupling the semi-analytical finite element (SAFE) as a forward method to the particle swarm optimizer. It is shown that accounting for the in-plane velocity component leads to a more accurate and robust determination of the orthotropic elastic stiffness parameters.
扫描激光多普勒振动测量技术是一种广泛采用的方法，用于测量材料的全场离面振动响应，以检测缺陷或估计刚度参数。最近的技术发展使得高性能的 3D 扫描激光多普勒振动计得以实现，该振动计可以获得离面和平面振动速度分量。在本研究中，研究了使用(i)平面分量；(ii)离面分量；以及(iii)记录的振动速度的平面和离面分量对刚度参数反演的影响。输入数据是通过有限元模型（COMSOL）的一系列数值模拟以及通过 3D 红外扫描激光多普勒振动计进行的宽带实验测量收集的。研究了各种材料，包括碳纤维环氧树脂复合材料和木材材料。通过傅里叶变换将全场振动速度响应转换到频波数域，然后使用矩阵束分解方法从该域中提取复波数。为了推断各向异性弹性刚度张量，通过将半解析有限元（SAFE）作为正向方法与粒子群优化算法耦合，开发了一种反演程序。结果表明，考虑平面速度分量可以更准确、更稳健地确定各向异性弹性刚度参数。
