Abstract The present work deals with multi-layer rectangular core topology systems built up by stacking layers made of different rectangular core geometries. Multi-layer systems have been intensively studied in terms of mechanical performances whereas their vibroacoustic behavior, acoustic efficiency and design is however still an open issue. Several design parameters should be considered to fully understand the dynamic and acoustic behaviour of such structures. Therefore, this paper focuses on controlling the transition frequency and the Sound Transmission Loss (STL) by modifying geometrical parameters of the unit cell, while keeping the mass constant. Infinite panels and real wavenumbers will be considered in the study. The Wave Finite Element Method (WFEM) is used to obtain the targeted indicators. The proposed designs give the opportunity to shift the transition frequency and to control the flexural waves propagating in the structure. Besides, the STL is highly improved in the full frequency range of interest compared to a standard sandwich panel made of a single core.

中文翻译：

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多层矩形核心拓扑系统的多尺度振动声学行为

摘要 目前的工作涉及通过堆叠由不同矩形磁芯几何形状构成的层而构建的多层矩形磁芯拓扑系统。多层系统在机械性能方面已经得到深入研究，然而它们的振动声学行为、声学效率和设计仍然是一个悬而未决的问题。应考虑几个设计参数以充分了解此类结构的动态和声学行为。因此，本文的重点是通过修改晶胞的几何参数来控制跃迁频率和声音传输损耗 (STL)，同时保持质量不变。研究中将考虑无限面板和实际波数。波浪有限元法（WFEM）用于获得目标指标。所提出的设计提供了改变过渡频率和控制在结构中传播的弯曲波的机会。此外，与由单芯制成的标准夹层板相比，STL 在感兴趣的整个频率范围内得到了极大的改进。