Bionic-Wheat Nonlinear Metastructure for Load-Bearing and Low-Frequency Vibration Isolation

Achieving both high static stiffness and low dynamic stiffness remains a challenge in structural design, limiting conventional vibration isolators in meeting the demands of high load-bearing and low-frequency isolation. Inspired by the natural bending structure of wheat, we propose a bionic-wheat nonlinear metastructure that integrates load-bearing capacity with low-frequency vibration suppression. A curved beam model is developed, and local resonant oscillators are introduced to target specific frequency bands. Using wave theory and structural dynamics, we derive the dispersion relation and reveal the nonlinear bandgap characteristics through numerical analysis. Finite element simulations and 3D-printed experiments validate the vibration isolation performance. Results show that large beam deformation enables broadband low-frequency isolation under high static loads, while local resonators suppress vibrations in designated bands. This study establishes a theoretical framework linking dispersion characteristics to load-dependent isolation behavior, offering insights into wave attenuation mechanisms in nonlinear metastructures. The proposed design provides a new strategy for developing high-performance vibration isolators with broad application potential in engineering scenarios requiring both high load capacity and low-frequency control.