利用模态技术分析伺服转台内框架设计的合理性

利用有限元法对超低速转台内框架进行了模态分析 ,并对有限元结果进行了试验验证 ,进而分析了结构设计合理性 ,较好解决了精密转台不宜进行常规模态试验的问题。在简述了转台内框架结构基础上 ,首先对有限元模态分析中模型建立方法进行了描述。分析了角接触球轴承支承刚度的求解方法 ,并提出在有限元中用合成刚度模拟实际轴承的支撑作用 ;描述了内框架有限元建模相关问题的处理方法 ;其次 ,给出了有限元分析结果 ,并在不破坏机械结构精度的前提下 ,利用模态试验对有限元分析结果进行了验证 ;最后 ,利用有限元结果分析了机械结构设计的合理性。本文通过对内框架模态分析研究证明了结构设计是合理性。

Rationality Research on Design of Inner Frame of Servo Turntable with Modal Analysis

The modal analysis of inner frame of high precision servo turntable with super-low speed is made by FEM method. The result of FEM analysis is testified by simplified experiment, and utilized to analyze the reasonability of the frame structure. After introduction of the frame, how to establish its FEM model is explained. To obtain the fashion of angular contact bearing used in model of FEM, the supporting stiffness of the bearing is discussed, and the composition stiffness used to replace the real structure of the frame in FEM is put forward. The result of FEM analysis of the frame is given and testified by experiment under the condition of assurance of the frame precision. Under given confines of dimensions, materials and weight, the deduction from the results of FEM shows that the design of the frame there are no distinct defects and the design of the frame is acceptable.