An archetypal zero- or quasi-zero-stiffness model with three degrees of freedom based upon an inverse method

Abstract

In this paper, a three degrees of freedom archetypal model with arbitrary designable features and its inverse construction method based upon the target restoring force functions are proposed. The construction conditions of the zero-stiffness and quasi-zerostiffness systems with 3-DOF have been studied in detail, by introducing the definitions of the zero-stiffness and the quasi-zerostiffness system, based upon the archetypal model. The static characteristic and the low-frequency vibration isolation performance of the quasi-zero-stiffness system with 3-DOF in arbitrary direction have been analyzed, by comparing with the linear system with the same support stiffness. The conclusion shows that there are finite solutions for the construction of 3-DOF zerostiffness characteristic, and infinite solutions for the construction of 3-DOF quasi-zero-stiffness characteristic, based on 3-DOF archetypal model and its dimensionless parameters. The feasibility of constructing the zero-stiffness system with 3-DOF will lead to a new inspiration for the design of the passive zero-stiffness support structures; and the low-frequency vibration isolation performance of the 3-DOF quasi-zero-stiffness system in arbitrary

Tunable integrated quasi-zero-stiffness metamaterials for ultra-low-frequency vibration isolation

“…QZS structure often exhibit nonlinear mechanical properties, within a specific displacement range, the overall stiffness of the structure no longer changes significantly with the increase of deformation, and the force-displacement curve shows a plateau trend [3]. Relying on the parallel connection of positive and negative stiffness mechanisms [4][5][6][7][8][9][10][11][12][13][14][15][16][17], mechanical QZS structures typically have good load-bearing capacity and excellent low-frequency characteristics, but their structure is complex and not compact, making it difficult to obtain good applications in small-scale spaces.…”