Tailored Mechanical Metamaterials with Programmable Quasi‐Zero‐Stiffness Features for Full‐Band Vibration Isolation

Abstract

Quasi‐zero‐stiffness (QZS) isolators of high‐static‐low‐dynamic stiffness play an important role in ultra‐low frequency vibration mitigation. While the current designs of QZS mainly exploit the combination of negative‐stiffness corrector and positive‐stiffness element, and only have a single QZS working range, here a class of tailored mechanical metamaterials with programmable QZS features is proposed. These programmed structures contain curved beams with geometries that are specifically designed to enable the prescribed QZS characteristics. When these metamaterials are compressed, the curved beams reach the prescribed QZS working range in sequence, thus enabling tailored stair‐stepping force‐displacement curves with multiple QZS working ranges. Compression tests demonstrate that a vast design space is achieved to program the QZS features of the metamaterials. Further vibration tests confirm the ultra‐low frequency vibration isolation capability of the proposed mechanical metamaterials. The mechanism of QZS stems solely from the structural geometry of the curved beams and is therefore materials‐independent. This design strategy opens a new avenue for innovating compact and scalable QZS isolators with multiple working ranges.

Double restabilization and design of force–displacement response of the extensible elastica with movable constraints

“…The design of structures displaying a prescribed force-displacement response is a challenge in the engineering of mechanical metamaterials [25,36,42,44]. An important example of such a device is the force-limiter, used to prevent unbounded growth of a force applied to a sensitive element.…”

“…Stability character of the non-trivial configurations and snap motion towards them have been assessed through the numerical solution of the nonlinear dynamic equations (43) and(44).…”

A brief review of metamaterials for opening low-frequency band gaps

“…One is to devise the mechanical structure to decrease the stiffness, and the other is to adjust the stiffness real-time. Introducing the negative stiffness mechanism [67,82] , decreasing the cross-section of the elastic material [56][57][83][84] , and adjusting the amount of compression [71][72]74,85] are the mechanical ways to change the resonator stiffness. Although these mechanical structures are in favor of obtaining band gap in the low-frequency range, these configurations are difficult to change once they were designed.…”

Ultra-Wide Bandgap in Two-Dimensional Metamaterial Embedded with Acoustic Black Hole Structures

“…Ruan et al provided a type of spiral phononic crystal for the low-frequency isolation on a ship [21]. Zhang et al reported a type of tailored Mechanical metamaterial with programmable quasi-zero-stiffness features for full-band vibration isolation [22]. Wu et al proposed a kind of mechanical metamaterials, which can circulate the energy between the metamaterial and the energy source, without passing energy to the payload [14].…”