局域共振子对手性覆盖层振动和声辐射抑制的影响

Influences of Internal Resonances on the Vibration and Sound Reduction of Chiral Layer Coating

为增强某些频率区域内覆盖层对加筋板的声辐射抑制作用,在手性结构覆盖层的圆环内填充软橡胶层包覆的金属核心局域共振子。本文基于有限元方法及Rayleigh积分公式,建立了敷设手性覆盖层加筋板简化梁模型,分析了手性覆盖层的振动抑制特性及局域共振子对手性覆盖层振动的影响。结果表明:手性结构的变形模式和局域共振子与手性结构之间的耦合作用对覆盖层的禁带频率带宽和振动衰减起到关键的作用;手性结构覆盖层对加筋板声辐射抑制作用主要来自于覆盖层的振动衰减能力,声辐射效率的变化对声辐射的影响较小。

To increase the bandwidth of the stop-band and the vibro-acoustic attenuation in the stop-band, the internal resonances with cylindrical cores coated by soft rubber chiral lattice were inserted in the nodes of the chiral structures. Based on the finite element method and the Rayleigh integration formula, the simplified beam models of the stiffened plate covered by a soft chiral lattice coating with or without internal resonances were built. The vibration and sound reduction characteristics of the chiral layer coating and the influences of the internal resonances on the vibration and sound characteristics of the chiral layer coating were analyzed. Results show that the deformation modes of the chiral lattice and its coupling effect with the internal resonances play a key role for the stop-band gap and the vibration attenuation. The vibration attenuation has a dominant contribution to noise reduction of the multilayer chiral lattice. And the sound radiation efficiency has little influence on noise reduction of the chiral layer coating.