Yan Bo, Wang Shangwen, Ling Peng, Yang Zhibo, Ma Hongye, Li Qinchuan
School of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Fundam Res. 2025 Feb 19;5(4):1505-1523. doi: 10.1016/j.fmre.2025.02.002. eCollection 2025 Jul.
The square exoskeleton of seahorses can transit linear motion into torsion to dissipate energy and protect the vertebrate when subjected to external disturbances. Inspired by the self-protection mechanism of the linear-to-torsion transition of the square exoskeleton of seahorses, a novel seahorse-exoskeleton-inspired structure (SES) is designed, which consists of two oblique rods and springs, and a rotational disc. The geometric relationship and dynamic model are established to reveal the corresponding nonlinear stiffness, adjustable high carrying capacity and large working range characteristics. The dynamic equation of the SES is derived according to the Lagrange equation and the frequency response relationship is obtained with the harmonic balance method. Then the effects of structural parameters on the nonlinear restoring force, nonlinear inertia, nonlinear quadratic force, nonlinear damping and the vibration isolation performance are studied comprehensively to achieve the low-frequency isolation characteristics. A SES prototype was manufactured and the corresponding experiment was carried out to verify the low-frequency vibration isolation performance of SES. The tested peak frequency of the unloaded SES can be lower to 1.48 Hz due to the linear-to-torsion property, which can generate torsional inertia and anti-resonance phenomenon. Furthermore, the nonlinear damping is positively correlated with input displacement. SES has a better vibration isolation performance under large excitation amplitude. This paper provides a guideline for the design of low-frequency bio-inspired vibration isolators with the linear-to-torsion transition mechanism.
海马的方形外骨骼能够将直线运动转化为扭转运动，以耗散能量，并在受到外部干扰时保护脊椎。受海马方形外骨骼从直线到扭转转变的自我保护机制启发，设计了一种新型的受海马外骨骼启发的结构（SES），它由两根斜杆、弹簧和一个旋转盘组成。建立了几何关系和动力学模型，以揭示其相应的非线性刚度、可调高承载能力和大工作范围特性。根据拉格朗日方程推导了SES的动力学方程，并用谐波平衡法得到了频率响应关系。然后，全面研究了结构参数对非线性恢复力、非线性惯性、非线性二次力、非线性阻尼和隔振性能的影响，以实现低频隔振特性。制作了一个SES原型，并进行了相应实验，以验证SES的低频隔振性能。由于具有从直线到扭转的特性，空载SES的测试峰值频率可低至1.48Hz，这会产生扭转惯性和反共振现象。此外，非线性阻尼与输入位移呈正相关。在大激励幅值下，SES具有更好的隔振性能。本文为具有从直线到扭转转变机制的低频生物启发式隔振器的设计提供了指导。
