某机床床身残余应力仿真分析研究

Residual Stress Simulation Analysis of a Machine Tool Bed

以某加工中心床身铸件为研究对象,提出一种基于残余应力影响的定位精度分析方法。首先对某加工中心床身进行铸造残余应力仿真分析,得到了床身残余应力云图;随后以铸造残余应力场为初始载荷,采用生死单元法模拟去除材料过程对导轨安装面变形进行了预测。结果表明,随着材料的逐层去除,导轨安装面变形挠度值变化不大,其最大变形量约为5μm,并呈上凸状。可知,床身毛坯初始铸造残余应力分布规律对床身导轨安装面加工变形具有重要影响。

Taking a machining center bed casting as the research object,a positioning accuracy analysis method based on residual stress is proposed.The casting residual stress simulation analysis of a machining center bed is carried out,and the residual stress cloud map of the bed is obtained.Using the casting residual stress field as the initial load,the birth and death element method is used to simulate the material removal process and the deformation of the rail mounting surface is predicted.The results show that with the layer-by-layer removal of the material,the deformation deflection value of the rail mounting surface does not change much,and the maximum deformation is about 5 μm,which is convex.It can be seen that the initial casting residual stress distribution law of the bed blank has an important influence on the machining deformation of the bed rail mounting surface.