A nonlinear vibration isolator with quasi-zero-stiffness inspired by Miura-origami tube

A nonlinear vibration isolator with quasi-zero-stiffness (QZS) is designed inspired by the bi-stable Miura-origami tube. The isolator comprises a negative stiffness element with four rods and one horizontal spring, while a vertical linear spring is used to provide positive stiffness. The static characteristics of the negative stiffness element are studied and then the design procedure for the QZS isolation system with a lumped mass is provided. The static displacement is considered as an input parameter to illustrate the high-static-low-dynamicstiffness (HSLDS) property of the isolator. To further display the isolation ability of the present isolator, the dynamic model of the system under base excitation is established with the linear air damping and nonlinear damping caused by rotational joints. The nonlinear terms are then approximated by Taylor series and the averaging method is used to predict the dynamic performance. The present theory is verified by comparing the system's free and forced responses under different frequencies of base excitation with those calculated by numerical simulation. The displacement transmissibility of the present nonlinear vibration isolator demonstrates the much improved vibration isolation performance as compared to its linear counterpart.

Automated summary

A nonlinear vibration isolator with quasi-zero-stiffness (QZS) is designed based on the bi-stable Miura-origami tube, featuring a negative stiffness element with four rods and a horizontal spring. The static characteristics and design procedure for the QZS isolation system with a lumped mass are studied, showcasing its high-static-low-dynamic stiffness property.