摘要
为能够隔离作用在负载上的直接扰动并提高系统的阻尼特性以避免产生共振,提出一种采用磁性负刚度机构设计的超阻尼隔振系统,其由磁性负刚度机构和两对相互对压的机械弹簧并联构成;磁性负刚度机构由五块沿轴向磁化的环形永磁体构成,倾斜环形永磁体被对称地固定在基础上,运动的环形永磁体由对压的机械弹簧约束,并沿轴向发生相对运动;根据电流模型,推导了磁性负刚度机构的磁性恢复力以及磁性负刚度解析表达式;通过将隔振系统中的刚度单元和阻尼单元重新布置并引入一个内部隐性自由度,该系统被设计成与线性参考系统具有相同静刚度、相同质量以及相同阻尼的超阻尼装置;分析了该装置中刚度单元、阻尼单元以及永磁体附加质量对所设计系统阻尼、固有频率和主系统振动响应的影响。研究结果表明,所提出的隔振系统具有高刚度和超阻尼特性,能够有效抑制主系统的振动;在高频段,主系统的响应将收敛于线性参考系统。
Abstract: In order to isolate direct disturbances exerted on payload and to improve damping properties of an isolation system for purpose of avoiding resonances, a hyper-damping vibration isolator was developed based on a magnetic negative stiffness mechanism. The mechanism consisted of a magnetic negative stiffness spring (MNSS) and two pairs of pre-pressured mechanical springs. MNSS included five magnetic rings axially magnetized, inclined magnetic rings were symmetrically mounted on the base, while a moving ring was constrained by two pre-pressured mechanical springs and was allowed to oscillate along the axial direction. The analytical expressions for magnetic restoring force and magnetic negative stiffness were further deduced according to the current model. By repositioning the stiffness and damping elements of the vibration isolation system, the vibration isolation system was deigned to be a hyper-damping device with the same static stiffness, the same damping and the same mass as those of a typical linear reference system. The impacts of stiffness elements, damping ones of the device and added mass of magnet on the damping, natural frequencies of the designed system and vibration responses of the main system were deeply analyzed. The results showed that the proposed vibration isolation system has high stiffness and hyper damping characteristics and it can effectively suppress vibrations of the main system; the response of the main system converges to that of the linear reference system in a higher frequency range. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第9期239-246,共8页
Journal of Vibration and Shock
基金
国家自然科学基金项目(11172225)
