Milling Rigid-plastic Finite Element Modeling And Simulation Analysis

With the application of milling process into the machining of new engineering materials and the development of milling process towards high speed and high precision,the milling data system based on the experience and experiments before become helpless.It is urgently needed to do some research on the basic theory of milling process and the interaction between the factors in milling process.After the basic principle in milling process is discussed,the paper tries to analyze the milling process by carrying out simulations using the three dimensional coupled thermal -mechanical model established with FEM.For establishing more exact finite element coupled thermal-mechanical model of milling process to carry out the simulation,firstly the basic principle and theory of milling process and the modeling theory with FEM are discussed in the paper.Based on the fact that the milling process can be regard as many oblique cutting processes along the milling cutter edge,the three dimensional rigid-plastic finite element coupled thermal-mechanical oblique cutting model is established to analyze the interaction between factors in milling process.After discussing the key techniques of finite element simulation of metal cutting,the adaptive remeshing based on error estimate is used in the simulation of oblique cutting.The stress,strain, actual cutting angle and the effect of inclination angle,tool-chip interfacial friction and cutting speed on the cutting force,cutting temperature and chip curling are analyzed through simulation.Compared with the oblique cutting theory,the method of simulation with FEM is more efficient,it can reflect the interaction between factors in metal cutting more directly.Finite element simulation is an effective tool to research the cutting process.Compared with oblique cutting,the milling cutter in milling process has more complicated geometrical shape and motion.For simulating the real milling process to reflect the actual variation in milling process,the three dimensional rigid-plastic finite element coupled thermal-mechanical model of flank milling process with end milling cutter is developed in the paper.The adaptive remeshing based on error estimate is also used to distribute larger mesh density in the area where the variable gradient is large near the cutting edge and smaller mesh density in the area where the variable gradient is small.This can reduce the numbers of element needed in the simulation under certain accuracy and reduce the computational time and make the three dimensional simulation become possible.And the milling force data collected from experiment is compared with that from the simulation with the finite element model developed,the result shows that the model is reasonable.The chip formation, milling force,milling temperature and the effect of helix angle on them in flank milling process with end milling cutter are analyzed at last through simulations using the model developed,this lays a foundation for the further application of finite element simulation into milling process.