Self-contacting overlay complementary multi-level multi-stable quasi-zero stiffness vibration isolation device

In most practical applications, isolators are required to simultaneously achieve excellent low-frequency vibration isolation performance and high load-bearing capacity. However, most reported vibration isolation metamaterials to date excel primarily in low-frequency isolation effectiveness, struggling to achieve substantial load-bearing capabilities. To address this challenge, inspired by the unique structure of plant petals, we propose a design strategy for a self-contacting complementary multi-level multi-stable vibration isolation device. This strategy utilizes the cumulative complementary effects of interlayer bending stiffness and contact enhancement behaviors in multi-layer structures to create quasi-zero stiffness (QZS) platform regions with significantly different load-bearing capacities. Additionally, through coupled interactions post-interlayer contact, energy dissipation capabilities are effectively enhanced, further bolstering load-bearing capacity. Furthermore, by extending the design of the multi-layer isolation unit, we introduce a design scheme for QZS-type local resonance metamaterials. By directly configuring mass blocks on mirror-symmetrically arranged isolators, we constructed a multi-stage stiffness QZS-type local resonance vibration absorption unit. Through systematic analysis employing dynamic theory, force field and wave field simulations, as well as experimental testing, we comprehensively verify the feasibility and effectiveness of the proposed designs. This advanced structural vibration isolation device could effectively satisfy practical engineering requirements for low-frequency vibration attenuation and reliable load-bearing strength, offering innovative solutions for equipment vibration reduction and noise mitigation design, with significant engineering application value.