Abstract:

Spiders can easily maintain a stable posture under external disturbances owing to the excellent anti-disturbance capability of spider webs. Drawing inspiration from the intrinsic topological features of the spider web, this paper proposes a biomimetic structure for low-frequency vibration isolation, a capability that remains challenging for traditional isolators. The rods and elastic ropes are utilized to mimic the radial threads and circumferential threads of the spider web to produce negative stiffness, while the repulsive magnets are adopted to produce hardening positive stiffness. Through a nonlinear compensation method, the entire isolator combining the rod-elastic-rope structure and the repulsive magnets is designed to possess quasi-zero-stiffness (QZS) characteristics with high tunability, thereby enabling effective low-frequency vibration isolation. The static analysis and dynamic modeling of the proposed spider-web-inspired (SWI) isolator are carried out to reveal the underlying principle, along with an exploration of its diverse nonlinear dynamic behaviors such as bifurcations and chaos. The vibration isolation performance is then comprehensively investigated, validating the superior low-frequency isolation capability of the SWI isolator.

Key words: biomimetic structure, nonlinear compensation method, quasi-zero-stiffness (QZS), vibration isolation