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为了研究手性蜂窝复合材料的振动特性与其振动传播带隙之间的关系,首先,建立了该种材料离散多自由度的夹杂-韧带振动力学模型,该模型考虑了其内嵌夹杂的局部振动与由微结构韧带连接的节点环之间的弹性耦联及诱发共振模态。然后,重点研究了微结构元件之间的耦联程度和微结构元件的尺寸参数对材料吸振带隙低频段和高频段的影响,并结合有限元方法对模型进行了验证分析。结果表明:除柔性包覆的夹杂以外,耦联诱发振动、节点环和韧带的材料及尺寸参数都对手性蜂窝复合材料的固有振动频率产生显著影响,从而控制带隙的位置和带宽。随着节点环内、外弹性耦联程度的减小,夹杂的模态频率将控制带隙的低频段,且随着夹杂质量的增大,低频段的频率降低;高频段由韧带振动表征;当节点环内、外弹性耦联程度增大时,带隙的低频段对韧带和框架的模态更加敏感,从而出现比夹杂模态频率更低的带隙。无论弹性耦合程度强弱,当韧带和节点环的厚度减小时,材料第三阶较高的包覆层变形频率将被相对更低的韧带振动频率取代。所得结论可为小尺寸、低频宽带隙手性蜂窝型隔振材料的设计研究提供理论指导。
In order to study the relationship between the vibration characteristics and the vibrational bandgap of chiral honeycomb composites, we first established a discrete multi-degree freedom mixed-ligament vibrational mechanical model of the material, which takes into account the embedded vibration Elastic coupling with node rings connected by microstructured ligaments and induced resonance modes. Then, the influence of the coupling degree between the microstructures and the size parameters of the microstructures on the low band and the high band of the band gap of the material is studied emphatically, and the model is verified with the finite element method. The results show that except for the flexible inclusion, the coupling-induced vibration, the material and the size parameters of the node rings and ligaments all have a significant effect on the natural frequency of the chiral honeycomb composite, so as to control the position and bandwidth of the band gap. With the decrease of elastic coupling inside and outside the node, the modal frequencies will control the low frequency band of the bandgap, and the frequency of the low frequency band decreases with the increase of the inclusion mass. The high frequency band is characterized by the ligament vibration. When the degree of elastic coupling inside and outside the node ring increases, the low frequency band of the bandgap is more sensitive to the modes of the ligament and the frame, resulting in a lower bandgap than the inclusion mode frequency. Regardless of the degree of elastic coupling, when the thickness of the ligament and node ring is reduced, the higher third-order cladding deformation frequency of the material will be replaced by a relatively lower frequency of ligament vibration. The conclusion can provide theoretical guidance for the design and research of small size and low band gap chiral honeycomb vibration-isolating materials.