考虑设备弹性的隔振系统

Isolation Effect of the System with Equipment Support's Flexibility

针对被隔振设备在高频域表现出的弹性阻抗特性,将设备中具有弹性性质的支撑部分模化为两端自由连续体,确定振源输出作为一个常力作用在设备支撑上,同时考虑设备支撑的刚体运动与弹性振动。采用导纳矩阵法对设备支撑的阻抗特性及隔振系统的功率流传递特性进行研究。结果表明,振源激励力在设备支撑上的位置对系统隔振效果具有较大影响。当激励力偏心时不仅引起系统横摇振动,还会激发设备支撑与基础的偶数阶模态,导致隔振效果变差。隔振器相对设备支撑中心或基础中心不对称布置会激发基础偶数阶模态,且前者还会导致垂向—横摇耦合振动。分析的结果对于弹性基础隔振效果的改善有参考价值。

The flexibility characteristic of the isolated equipments in high frequency domain is studied.A model,in which the elastic support of the equipment is regarded as a continuum system with free ends,is established.The vibration source output is regarded as a constant force applied to the equipment＇s support,and its rigid motion and elastic vibration are considered.Then,the characteristics of the flexible equipment＇s support and the power flow transmission of the vibration isolation system are studied utilizing admittance matrix method.It is shown that the position of the source excitation has a great influence on the performance of the vibration isolation system.The eccentricity of the excitation force can induce lateral oscillation of the system and inspire even order modes of the support and the base,which will lead to poor isolation effect.The non-symmetric distribution of the isolators to the central line of the support or the base can excite the even order modes of the base,and the former can furthermore inspire lateral-pitch coupled oscillation.Results of the analysis may have some reference significance for improvement of vibration isolation of equipments with flexible supports.