Study On Finite Element Simulation Of Milling Deformation Of Large Curved Structure Of High-speed Train

Large curved structure is an important part of the high-speed train head,which has the characteristics of simple assembly and small wind resistance.The manufacturing of large curved surface structure parts has become one of the most prominent problems in the rapid development and high efficiency production of high-speed train equipment.Because of the large volume,many curved surfaces and poor rigidity of these parts,the deformation of these parts is too large in milling process.The path of cutter and the clamping mode of the workpiece are one of the main reasons for the deformation of such large parts.This paper makes a systematic simulation calculation of the influence of the path planning,clamping and supporting mode on the machining deformation of large curved surface structural parts during milling process.The main research contents and results are as follows:(1)In view of the milling force simulation of aluminum alloy large curved structure parts,the method of introducing the tool path of finite element milling simulation was proposed.The tool path of milling large curved structure parts was programmed,and the obtained tool path was imported into the finite element simulation by means of amplitude plug-in for the milling force simulation.Based on the analysis of the change of milling force following the curvature of curved surface,the change law of milling force of large curved surface structure was obtained.The local deformation law of large curved surface structure in the process of milling cutter movement was determined through the simulation study of milling deformation.(2)According to the surface characteristics and material characteristics of aluminum alloy large curved surface structural parts,a model suitable for the milling deformation research of large curved surface structural parts was established,and the milling area was divided according to the changing characteristics of milling force of large curved surface.Based on the results obtained from the three-dimensional milling force simulation,it was imported into the blank parts.The failure treatment of the parts to be machined was carried out by using the birth and death element method,and the milling process was simulated.The simulation analysis of forces in the milling process of "Z","outer ring" and "symmetrical" tool paths was designed,and the influence law of the cutting way on the deformation of large curved structural parts was obtained.The results show that the deformation of the symmetric cutting way is less than that of the traditional "Z" cutting way.(3)The commonly used support and clamping methods of large-scale curved structural parts in the milling process are analyzed,and the geometric structure characteristics and clamping support requirements of large-scale curved structural parts are calculated.Through the simulation of the deformation degree of the workpiece after milling,the best supporting mode is obtained by simulating the six existing clamping distribution forms.Under the premise of ensuring the reliable clamping of large curved surface structure parts,the deformation caused by milling force and clamping force is the minimum;Through the test of auxiliary support on the weak part,the best distance between the auxiliary supports is obtained.The above research is of great significance to reduce the deformation caused by machining process,and it is also of reference significance for the research of milling finite element analysis method for large curved surface structure.