超微颗粒碰撞阻尼的混沌控制及应用理论

During the one-year preliminary study， we focused our study on the chaotic dynamics and control of the impact dampers with particles as damping agent (IDPDA) according to the research plan。Influences of the main parameters ，such as restitution and friction coefficients，clearance，and particle size on the damping is analyzed。The damping structure is identified by means of neural networks。Illustrations show that by parameter control we can keep the motion of the impactor and the.container in phase to eliminate harmful chaos introduced by the impacts。At the same time， the particle agent can absorb the vibration energy irreversibly in the following manner：Fragile or coarser particles are easy to be broken up, and plastic or finer particles tend towards full plastic.deformation during the process. The higher the excitation level, the stronger the irreversible energy sinks. Therefore, the IDPDA have significant hardening non-linearity. Experiments show that for steady state motion the IDPDA can reduce the response of the primary structure by 99.5%,which is to date the largest attenuation published. In addition, by diminishing friction effects with lubricant particles we can control the sub-harmonic excitation or sub-harmonic amplification successfully in the range of resonance or low frequencies existing in conventional impact dampers。In a word，new concept and mechanism are proposed for the development of impact damping。.We summary the following as our achievements：（1） For the first time the mechanism of particle breakage is utilized to dissipate vibration energy。（2） For the first time lubricant particles are introduced to overcome friction in order to control the non-stability of conventional impact dampers in resonance or low frequency range。

本项目旨在探索超微颗粒碰撞阻尼器的混沌控制及应用机理，其中颗粒的原始中值粒度达数微米及其以下。重点探讨具有低频密集模态的非线性系统的宽带非反射（即振动能量全部吸收，不在系统内传递和反射）振动控制理论。本项目对振动控制工程，超微颗粒的研究与应用，以及细观力学等交叉学科和高新技术的发展具有重要的和深远的意义。......