Influencing the dynamic properties of weakly damped structures through systematic design of linear and non-linear metamaterials

周期性荷载会导致技术结构的振动激励，其中轻薄构件受到的影响尤为明显。如果阻尼也是不均匀分布的，即局部集中，则结构在激励和局部阻尼之间发生波动动力学。在这种情况下，传统的减振方法往往不再足够。影响这种结构的动力学的一个很有前途的方法是使用超材料。超材料是周期性排列的子结构，它们本身能够振动，不仅影响模态参数，而且还影响波传播的频率范围。在这个项目的范围内，将系统地设计超材料，有意地包括非线性子结构。为此，采用和转换了非线性动力学的方法。目标是使用具有复杂边界条件的有限元模型来描述周期性子结构的一般设计。为了验证，制作了线性和非线性的超材料梁结构，并进行了实验研究。为了能够研究同样可重现的行波，将分析压电元件和声学黑洞的组合，并将其用作局部能量汇。有了这些知识，非线性变幅元结构的系统设计将有可能对结构的动力特性产生更大的影响。

Periodic loads lead to vibration excitation in technical structures, whereby light and thin components are particularly affected. If the damping is also distributed inhomogeneously, i.e. locally concentrated, wave dynamics occur in the structure between excitation and local damping. Classical means for vibration reduction are often no longer sufficient in this case. A promising approach to influence the dynamics of such structures is the use of metamaterials. Metamaterials are periodically arranged substructures which are themselves able to oscillate and which influence not only modal parameters but also frequency ranges of wave propagation. Within the scope of this project, metamaterials will be systematically designed, intentionally including nonlinear substructures. For this purpose, methods of nonlinear dynamics are adapted and transferred. The objective is a general design using finite element models with complex boundary conditions to describe the periodic substructures. For validation, linear and nonlinear beam structures with metamaterial are produced and experimentally investigated. In order to be able to study also reproducible travelling waves, a combination of piezo elements and acoustic black holes will be analyzed and used as local energy sinks. With the knowledge gained, a systematic design of nonlinear amplitude-dependent metastructures will be possible for an extended influence on structural dynamic properties.