Abstract In this manuscript we experimentally study a modular metamaterial that is able to provide mechanical insulation for elastic wave propagation. Specifically, the structural design is based on the modes separation principle, that entails the presence of ultra-wide bandgap at low frequencies, also in presence of few lattice elements. In this paper, we present a simple manufacturing process for the unit cell realization. This method, however, introduces imperfections given by folding and bonding operations: we demonstrate that upon a careful unit cell design and thanks to modes separation, the presence of defects is not relevant from the dynamical point of view and does not alter the filtering behavior. Moreover, we consider a simple assembly with repetition along a single direction, in order to investigate the metamaterial robustness with respect to the lack of 3D periodicity. Experimental data are compared to numerical simulations demonstrating the advantages of such design for real-life vibration isolation problems.

中文翻译：

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基于模式分离的不完美 3D 模块化结构中的宽低频带隙

摘要在这份手稿中，我们通过实验研究了一种能够为弹性波传播提供机械绝缘的模块化超材料。具体来说，结构设计基于模式分离原理，这需要在低频下存在超宽带隙，并且存在很少的晶格元素。在本文中，我们介绍了一种用于实现单元电池的简单制造工艺。然而，这种方法引入了折叠和键合操作带来的缺陷：我们证明，在仔细的单元设计和模式分离的基础上，从动力学的角度来看，缺陷的存在并不相关，并且不会改变过滤行为。此外，我们考虑一个沿单一方向重复的简单装配，为了研究缺乏 3D 周期性的超材料鲁棒性。实验数据与数值模拟进行了比较，证明了这种设计对于现实生活中的隔振问题的优势。