Journal Article

Nonlinear dynamic behavior of a bionic quasi-zero stiffness isolation system inspired by cobweb with the amplification effect

Bai, Jinlin, Yuan, Junjie, Jin, Guoyong, Sun, Zexi, Ye, Tiangui

2024

Overview

Inspired by the hunting strategy of spiders utilizing cobwebs, this study proposes a novel bionic cobweb structure (BCS) that facilitates the layer-by-layer nonlinear amplification of physical attributes for its embedded isolation components. By integrating a conventional quasi-zero stiffness (QZS) isolator within the BCS, a bionic QZS isolation system is achieved, exhibiting amplified negative stiffness and damping characteristics. The influences of BCS parameters on negative stiffness and damping are systematically investigated. A dynamic equation of the isolation system is formulated, incorporating the cubic trinomial stiffness and cubic quadrinomial damping terms. The displacement transmissibility is derived by the average method and verified via the Runge–Kutta method. The results manifest the effectiveness of the BCS nonlinear amplification effect on the enhancement of vibration isolation performance, accompanied by good coupling between the amplified negative stiffness and damping. Increasing the number of BCS layers, enlarging the initial angle θ i of the i-layer BCS, augmenting the pre-compression δ 20 of the negative stiffness springs, and shortening the connecting rod L s , synergistically contribute to a superior amplification of negative stiffness for better counterbalancing the substantial positive stiffness encountered in heavy-load scenarios. Furthermore, the amplified damping exhibits an anti-resonant characteristic, effectively mitigating the hardening nonlinearity without compromising high-frequency performance. The constructed bionic QZS isolation system with the BCS outperforms the initial QZS system in terms of resonance frequency, peak transmissibility, and isolation frequency band. Moreover, the proposed BCS has the prospect of emerging as a usual platform without modifying the current isolation elements. The intrinsic amplification effect and design logic can offer heuristic insights for future research.

• Publisher: Springer Netherlands,Springer Nature B.V
• Subject: Amplification / Automotive Engineering / Bionics / Classical Mechanics / Connecting rods / Control / Deformation / Dynamical Systems / Engineering / Frequencies / Isolation systems / Mechanical Engineering / Nonlinear dynamics / Nonlinearity / Original Paper / Polynomials / Runge-Kutta method / Springs (elastic) / Stiffness / Vibration / Vibration damping