Metamaterials (MMs) are composites that are artificially engineered to have unconventional mechanical properties that stem from their microstructural geometry rather than from their chemical composition. Several studies have shown the effectiveness of viscoelastic MMs in vibration attenuation due to their inherent vibration dissipation properties and the Bragg scattering effect. This study presents a multiobjective optimization based on genetic algorithms (GA) that aims to find a viscoelastic MM crystal with the highest vibration attenuation in a chosen low-frequency range. A multiobjective optimization allows considering the attenuation due to the MM inertia versus the Bragg scattering effect resulting from the periodicity of the MM. The investigated parameters that influence wave transmission in a one-dimensional (1D) MM crystal included the lattice constant, the number of cells and the layers’ thickness. Experimental testing and finite element analysis were used to support the optimization procedure. An electrodynamic shaker was used to measure the vibration transmission of the three control specimens and the optimal specimen in the frequency range 1–1200[Formula: see text]Hz. The test results demonstrated that the optimized specimen provides better vibration attenuation than the control specimens by both having a band-gap starting at a lower frequency and having less transmission at its passband.

中文翻译：

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减振特性的粘弹性超材料优化

超材料 (MM) 是经过人工设计的复合材料，具有非常规的机械性能，这些机械性能源于其微观结构几何而不是其化学成分。由于其固有的振动耗散特性和布拉格散射效应，一些研究表明粘弹性 MM 在振动衰减方面的有效性。本研究提出了一种基于遗传算法 (GA) 的多目标优化，旨在找到在选定的低频范围内具有最高振动衰减的粘弹性 MM 晶体。多目标优化允许考虑由于 MM 惯性引起的衰减与由 MM 的周期性引起的布拉格散射效应。影响一维 (1D) MM 晶体中波传输的研究参数包括晶格常数、单元数和层厚度。实验测试和有限元分析用于支持优化过程。采用电动振动台测量三个对照试件和最佳试件在1-1200[公式：见正文]Hz频率范围内的振动传递。测试结果表明，优化后的样品提供了比控制样品更好的振动衰减，因为它具有从较低频率开始的带隙和在其通带具有较少的传输。采用电动振动台测量三个对照试件和最佳试件在1-1200[公式：见正文]Hz频率范围内的振动传递。测试结果表明，优化后的样品提供了比控制样品更好的振动衰减，因为它具有从较低频率开始的带隙和在其通带具有较少的传输。采用电动振动台测量三个对照试件和最佳试件在1-1200[公式：见正文]Hz频率范围内的振动传递。测试结果表明，优化后的样品提供了比控制样品更好的振动衰减，因为它具有从较低频率开始的带隙和在其通带具有较少的传输。