Simon Alverède, Baudis Quentin, Wunenburger Régis, Valier-Brasier Tony
Centre National de la Recherche Scientifique (CNRS), Institut Jean Le Rond d'Alembert, Sorbonne Université, F-75005 Paris, France.
J Acoust Soc Am. 2024 Jun 1;155(6):3627-3638. doi: 10.1121/10.0026233.
The propagation of coherent longitudinal and transverse waves in random distributions of spherical scatterers embedded in an elastic matrix is studied. The investigated frequency range is the vicinity of the resonance frequencies of the translational and rotational motion of the spheres forced by the waves, where strong dispersion and attenuation are predicted. A technique for making samples made of layers of carbide tungsten beads embedded in epoxy resin is presented, which allows control of the scatterers distribution, induce short-range positional correlations, and minimize the anisotropy of samples. Comparison between phase velocity and attenuation measurements and a model based on multiple scattering theory (MST) shows that bulk effective properties accurately described by MST are obtained from three beads layers. Besides, short-range correlations amplify the effect of mechanical resonances on the propagation of longitudinal and transverse coherent waves. As a practical consequence, the use of short-range positional correlations may be used to enhance the attenuation of elastic waves by disordered, locally resonant, elastic metamaterials, and MST globally correctly predicts the effect of short-range positional order on their effective properties.
研究了相干纵波和横波在嵌入弹性基体的球形散射体随机分布中的传播。所研究的频率范围是由波驱动的球体平移和旋转运动的共振频率附近，预计在此处会有强烈的色散和衰减。提出了一种制作由嵌入环氧树脂的碳化钨珠层制成的样品的技术，该技术能够控制散射体的分布，诱导短程位置相关性，并使样品的各向异性最小化。相速度和衰减测量结果与基于多重散射理论（MST）的模型之间的比较表明，从三个珠层获得了由MST准确描述的体有效特性。此外，短程相关性放大了机械共振对纵向和横向相干波传播的影响。实际结果是，短程位置相关性的使用可用于增强无序、局部共振的弹性超材料对弹性波的衰减，并且MST全局正确地预测了短程位置有序对其有效特性的影响。
