三自由度并联机床动态有限元分析

对并联机床进行动态性能分析有着重要意义。应用工程分析软件,建立了一种三自由度并联机床整机的有限元模型,对整机进行了模态分析,提取了整机前十阶固有频率和振型。为了解各阶频率对机床动载荷的响应情况,在模态分析的基础上对整机进行了谐响应分析,得到了动平台、球铰、滑鞍等关键部位的频率位移响应曲线。分析结果表明,机床的第2阶和第4阶固有频率对机床动态性能影响最大。球铰结合部为机床结构中薄弱环节,由此提出了机床结构优化设计建议,将球形铰链更换为虎克铰链,从而提高了机床的动态性能。

Dynamic Finite Element Analysis for the Three Degrees of Freedom Parallel Machine Tool

The dynamic characteristic analysis is very meaningful for parallel machine tool.Using engineering analysis software,the finite element analysis model of three degrees of freedom parallel machine tool was established,modal analysis of whole machine was carried out,ten former natural frequencies and virbration modes were gained.In order to uderstand all steps frequency moved the loaded response situation to the machine,hamonic response to the whole machine was analyzed,response curve of frequency and displacement for key components such as moving platform,spherical hinges and slide saddle was gained.The results show that the most influential frequencies of the dynamic performance are the second step frequency and the fouth step frequency.The weak link of the machine are spherical hinges jonnts,therefore optimization sugesstions for machine’s structure design were proposed,then chang spherical hinges for hook joints to improve the dynamic performance.