Bio-inspired Nonlinear Inertia Systems for Passive Vibration Isolation: Modelling, Analysis, Design, and Realization

Description

During walking, running and jumping, human bodies can work as a very excellent vibration isolator to prevent brain injuries, and the peak frequency tends to be much lower than 3 Hz with knees bending appropriately, due to elastic muscles and foldable tendon-bone structures of legs. Noticeably, arm swinging is actually playing a critical role in gait control, because it does not only maintain body stability but also suppress vibration transmission. More interesting, human arms can be extended or collected to achieve changing leverage ratio to better control body stability; the tension of arm muscles can be purposely tuned to obtain a changing stiffness during arm swing for better body balancing; making a fist or extending palms periodically can lead to varying equivalent mass during dynamic body control in fast motion; and also, a jumping body with frequently waving arms or legs in air can prolong the forward moving inertia (well employed by athletes). However, all those inertial features have never been fully explored in the literature for engineering vibration control.Our preliminary studies reveal that nonlinear inertia is very advantageous to balance the interactive force during a vibration cycle with appropriate design of a specially prototyped inertial unit. However, in what frequency range and what nonlinear inertia functions/modes can bring what kind of advantages to vibration control are still far from being fully understood, and thus more detailed understanding and modelling efforts are yet to be done. Therefore, this project is aimed to explore much more effective mechanisms of nonlinear inertia, to develop systematic modelling, analysis, and design methods for a more in-depth understanding of nonlinear influence incurred by inertia nonlinearity, and definitely to bring innovative vibration control technology to extensive engineering practices eventually. The deliverables will present totally new design and associated analysis methods for nonlinear inertial systems both in frequency and time domains, reveal unique and explicit math models of beneficial inertial nonlinearities, and provide significant insights or understanding into the advantageous nonlinear role that nonlinear inertia could bring to vibration control.For all kinds of engineering vibration control, including vibration isolation mounts and absorbers in civil engineering (buildings, bridges, marine platforms), aerospace systems, manufacturing factories, and noise & vibration control of various running machines and vehicles (e.g., hand-held jackhammers, vehicle seats, suspensions), the project results can all be well applicable and provide alternative and innovative solutions of high performance and minimized costs compared to existing ones.