基于虚拟材料法的六自由度并联机床静刚度研究  

Stiffness research of 6-DOF parallel machine tool based on virtual material method

作　　者：罗辉 彭宝营[1] 王鹏家 朱昱硕 LUO Hui;PENG Baoying;WANG Pengjia;ZHU Yushuo(Mechanical Electrical Engineering School,Beijing Information Science&Technology University,Beijing 100192,China)

机构地区：[1]北京信息科技大学机电工程学院,北京100192

出　　处：《北京信息科技大学学报（自然科学版）》2023年第1期76-81,共6页Journal of Beijing Information Science and Technology University

基　　金：国家重点研发计划子课题(2021YFC2400302);北京市教委科技计划一般项目(KM202011232012);宁夏自然科学基金资助项目(2022AAC03344)。

摘　　要：六自由度并联机床运动学模型比较复杂,并且由于零件结合面之间存在间隙、粗糙度、受力情况等不确定性因素,其刚度难以采用数学方法直接计算。针对这一难题,采用了一种结合实验、虚拟材料法、有限元分析的研究方法,建立了等效且简化的有限元模型,能够准确计算机床在不同位姿下的静刚度,得到了机床工作空间内的刚度变化规律。结果表明,机床活动平台由中心向外水平移动时Z向刚度下降较快,垂直向下移动时X、Y向刚度下降较快,而平台转动时刚度呈现较复杂的变化情况,这一分析为并联机床的结构改进及切削工艺优化提供了理论基础。The kinematic model of the six degrees of freedom(6-DOF)parallel machine tool is complex, and its stiffness is difficult to be directly calculated by mathematical method due to the uncertainty factors such as clearance, roughness and force between the joint surfaces of parts.In order to solve this problem, a research method combining experiment, virtual material method and finite element analysis was used to establish an equivalent and simplified finite element model, which can accurately calculate the static stiffness of the machine tool among different poses, and obtain the stiffness variation rule of the machine tool workspace, avoiding the difficult problem of complicated mathematical modeling and low accuracy.The results show that the Z-direction stiffness decreases rapidly when the platform moves horizontally from the center to the outside, while the X-direction and Y-direction stiffness decreases rapidly when the platform moves vertically down, and the movable platform stiffness presents complex changes when rotating.This analysis provides a theoretical basis for the improvement of the structure of the parallel machine tool and the optimization of the cutting process.

关 键 词：六自由度 并联机床 刚度 虚拟材料 有限元分析 

分 类 号：TG502[金属学及工艺—金属切削加工及机床]