基于ANSYS的高速加工中心有限元分析.pdf

摘要
高速加工中心是近年来机床发展的热点之一。随着加工中心向着高切削速度、高进
给速度和高加工精度的方向发展,对其工作性能的要求越来越高,不仅要求加工中心具
有良好的静态特性,而且要具有良好的动态特性。为此,对加工中心进行整机静动态特
性分析已成为设计的必要环节。
本文分析了焊接型和铸造型两种高速加工中心的主要结构特点,利用有限元分析软
件 ANSYS 分别建立了焊接型 EQD18 加工中心和铸造型 PM50A 加工中心的整体有限元
分析模型,对加工中心存在的两种不同类型的结合面,即螺栓联接的固定结合面和导轨
联接的运动结合面,采用用户自定义单元进行模拟;对加工中心驱动 X、Y、Z 轴高速
移动的传动丝杆,分别采用杆、梁单元进行模拟,并对比分析了两种模拟方法对加工中
心固有频率的影响,通过实验表明采用杆单元进行模拟更符合实际情况。
通过静力分析,模态分析和谐响应特性分析得到加工中心在不同工况下的静刚度、
动刚度、固有频率以及相应的振型等理论数值。并将 EQD18 加工中心的有限元分析结
果与实验数据进行了对比分析,证明了采用的有限元模型能较好地模拟实际情况,研究
成果为高速加工中心的设计提供了可靠的理论依据。

关键词:高速加工中心有限元分析静力分析模态分析谐响应分析
I
Abstract
With the development of high-speed machine centers toward the high-speed cutting,
high-speed feeding and high machining accuracy, the high-speed machine center is designed
more and plexly. The high-speed machine centers are required not only to have
good static property but also to have good dynamic property. For the design of high-speed
machine center it is necessary to be carried out the finite element analysis and predict the
static and dynamic response.
The main structure characteristic of the two types of high-speed machine centers, the
welded EQD18 and cast PM50A types are analyzed pared. The finite element model
of the two machine centers are built with the finite element software ANSYS. The fixing and
moving contact surfaces in the machine centers are simulated using the user-defined element.
The driving screws are simulated as the bar element and the beam element respectively. The
effects of the two kinds of element on the natural frequency of the machine centers are
analyzed. Comparing the analysis result with the experimental result, it is proved that the bar
element is more conformed to the real machine center.
The static, modal and harmonic responses of the machine center models are analyzed
using the finite element model proposed. The static stiffness, the dynamic stiffness and the
natural frequency of the two types of machine centers are calculated