BKX-I型并联机床的实验模态分析

The Experimental Modal Analysis of the BKX-I Model PKM

应用锤击法和基于变时基采样的SIMO法 ,对BKX -I型并联机床进行了模态实验 ,分别获得了机床沿x、y、z方向和机床整体结构的低阶固有频率、振型、阻尼比以及相应的振型动画。在此基础上 ,对该并联机床动态特性的特点进行了分析 ,明确了该机床动态特性的几个特点 ,确定了该机床的薄弱环节 ,并提出了提高并联机床动态特性的具体措施 。

Via using hammer-hitting method and varied time base sampling based SIMO method, the modal analysis of the BKX-I parallel kinematic machine based on Stewart mechanism is made in this paper. The lower orders natural frequencies, modes of vibration, damper rates and animations of relevant modes of vibration along the axes of x, y and z and whole structure are obtained, and the dynamic characteristic of this PKM is analyzed. On this basis, several specialties of dynamic characteristic are got and the structure’ weakness is confirmed. All of these provide the basis for dynamic design and optimal design of the machine’s structure.