High-resolution analysis of the complex wave spectrum in a cylindrical shell containing a viscoelastic medium. Part II. Experimental results versus theory
High-resolution analysis of the complex wave spectrum in a cylindrical shell containing a viscoelastic medium. Part II. Experimental results versus theory
复制标题
对含有粘弹性介质的圆柱壳中的复杂波谱进行高分辨率分析。
DOI：
10.1121/1.419957
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
J. Dual
中科院分区：
文献类型：
--
作者：
J. Vollmann;R. Breu;J. Dual
测量了含不同粘弹性介质的圆柱壳中轴对称波模的复频谱。为此，将高分辨率激光干涉仪与现代谱估计方法相结合，发展了一种新的测量技术。为了分解复数与波数的关系，实现了复数谱估计方法。在1 kHz到2 MHz的频率范围内，同时分解了多达40条行波、轴对称模式的色散曲线。导波由压电式换能器激励。线弹性可以被视为粘弹性的极端情况(与变形周期相比，松弛时间较长)。为了验证理论的有效性，计算了含有粘弹性材料的壳体的色散曲线，并与各向同性铝棒的测量曲线进行了比较。“后向波传播”的现象……
The complex frequency spectrum of axisymmetric wave modes in a circular cylindrical shell containing various viscoelastic media is measured. A new measurement technique has been developed for this purpose by combining a high-resolution laser interferometer with modern spectrum estimation methods. To decompose the complex wave-number dependence, a complex spectrum estimation method has been implemented. Up to 40 dispersion curves of traveling, axisymmetric modes are decomposed simultaneously in a frequency range between 1 kHz and 2 MHz. The guided structural waves are excited by piezoelectric transducers. Linear elasticity can be considered as an extreme case of viscoelasticity (long relaxation times compared with the deformation periods). To ascertain the validity of the theory, dispersion curves are calculated for a shell containing a viscoelastic material behaving like the elastic shell and are compared with the measured curves of an isotropic aluminium rod. The phenomenon of “backward wave propagation,...