基于模态分析的并联机床动态特性的研究

Research on Dynamic Characteristics of Parallel Machine Tool Based on Modal Analysis

振动问题是影响并联机床加工精度的原因之一,研究并联机床的动态特性,可以为机床减振技术的研究提供理论基础。以三平动非对称冗余驱动(3-2SPS)并联机床为研究对象,建立并联机床的振动学模型,运用达朗贝尔原理与一阶影响系数矩阵建立机构多自由度振动系统的微分运动方程,通过ANSYSWorkbench对机床进行模态分析,分析机床的前6阶固有频率与振型,同时利用MATLAB对影响机床振动特性的前3阶固有频率的分布进行仿真分析,研究得出了机床的前6阶固有频率,确定了机床振动过程中相对形变较大的位置以及机床振动中的薄弱环节,研究结果为并联机床减振技术的研究提供了理论依据。

Vibration problem is one of the reasons that affects the machining accuracy of parallel machine tools.Studying the dynamic characteristics of parallel machine tools can provide a theoretical basis for the research of machine tool vibration reduction technology.Taking the three-parallel asymmetric redundant drive (3-2SPS) parallel machine tool as the research object,the vibration model of the parallel machine tool is established,and the differential motion equation of the multi-degree-of-freedom vibration system is established by using the D′Alembert principle and the first-order influence coefficient matrix.Through the ANSYS Workbench,the modal analysis of the machine tool is carried out,and the first 6 natural frequencies and vibration modes of the machine tool are analyzed.At the same time,the distribution of the first three natural frequencies affecting the vibration characteristics of the machine tool is simulated by MATLAB.The first six of the machine tools are obtained.The natural frequency of the order determines the position of the relatively large deformation during the vibration process of the machine tool and the weak link in the vibration of the machine tool.The research results provide a theoretical basis for the research of the vibration reduction technology of the parallel machine tool.