Customized design of periodic metacushion with quasi-zero-stiffness for low-frequency vibration isolation

Abstract

This paper develops an inverse design approach for periodic metamaterial with quasi-zero-stiffness (QZS) based on topology optimization. The customized design of QZS metacushion is realized with prescribed structure size and porosity factor. Finite element simulations (FEM) are performed on the optimized topological configuration while experiments are conducted on the fabricated periodic metacushion. Good agreement of force–displacement curves between two methods confirms the QZS feature in the quasi-static test. Vibration simulations and experiments validate the ability of periodic QZS metacushion on low-frequency vibration isolation. Moreover, the load-bearing capacity rises proportionally while the vibration isolation frequency drops with an increase of cell number in periodicity. In vibration tests, the deviation of objective payload significantly increases equivalent dynamic stiffness of metacushion, thus reducing the effect of vibration isolation in low-frequency ranges. In particular, the employment of periodic boundary in topology design results in lower frequency of vibration isolation as well as stronger robustness under non-uniform load, in comparison with free boundary. This work may provide an alternative approach for full-band vibration attenuation through the customized design of periodic QZS metacushion.