Lever-type inertial amplification plates for low-frequency vibration reduction

• Published in: Thin-walled structures 2023-11, Vol.192, p.111131, Article 111131
• Main Authors: Xi, Chenyang, Zheng, Hui, Mi, Yongzhen, Yu, Xiang
• Format: Article
• Language: English
• Subjects: Inertial amplification; Lever-type; Low frequency; Multi-level; Vibration reduction
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2023.111131

•Lightweight and compact lever-type inertial amplification plates are proposed.•The proposed plate possesses excellent low-frequency vibration reduction performance.•The vibration reduction performance of the plates presents pronounced directivity.•Multi-level mechanism is proposed for space-saving requirements.•Experiments validate the low-frequency vibration reduction performance of the plates. In this work, a lever-type inertial amplification (LIA) metastructure is proposed to enhance the vibration reduction capability of thin plates in the low-frequency range. The mechanism consists of a rigid lever hinged on the host plate at two separate locations and a small mass mounted at the end of the lever. Band-structures of the unit cell and vibration transmissibility of the finite LIA plate are computed by using the combination of analytical method and finite element method. Numerical results show that compared with the local resonant (LR) plates with the same added mass, the proposed LIA plates generate wider and deeper complete bandgaps at the same target frequency. The Bragg bandgaps occurring at higher frequencies are also broader compared with those of the LR plates due to a stronger impedance mismatch between the host plate and the attachments. Moreover, the vibration reduction performance of the LIA plate presents unique direction-dependent characteristics: maximum vibration attenuation is achieved when the LIA mechanisms are installed parallel to the wave propagation direction. To address the issue that single-level LIA takes up too much space to install, a multi-level LIA design is proposed. On one hand, the multi-level design makes the LIA mechanisms much more compact without hampering their vibration reduction performance; on the other hand, the combination of sub-levels greatly enhances the design flexibility of LIA mechanisms. Finally, experiments are performed to further confirm the vibration reduction performance of the proposed LIA plates. [Display omitted]