Research On Physical Simulation Of Ball-end Milling Process

In order to meet the requirement for the development of advanced manufacturing, the dissertation deals with the ball-end milling in the Virtual Manufacturing technique by means of differential geometry, metal cutting theory and machine tool testing technology, computer graphics and computer simulation technology, etc. Emphases are placed on the modeling and simulation of milling force, the milled surface generation mechanism and milled surface topography simulation method. The creative contributions may be summarized as follows:(1) In the aspect of describing the geometry of the ball-end mill, the parametric formula of cutting edge and local coordinates & relative vector expressions for constant lead ball-end mill are induced.(2) In the aspect of modeling and simulation of milling force, based on an approach for describing the ball-end mill. Moreover, a three-dimensional ball-end milling force model is formulated and corresponding milling force coefficients identification algorithm is developed.(2) In the aspect of milled surface generation theory and simulation for milled surface topography, a milled surface generation model for the ball-end milling is proposed and formulated. In the mean time, the corresponding simulated three-dimensional surface topography and contour are graphically presented. The trajectory equation of cutting edge relative to work-piece is derived. Then a three-dimensional topography simulation algorithm is developed through dividing the work-piece into regular grids. This algorithm can completely emulate the milling process. Finally, the quality of the milled surface is evaluated by means of RMS (Root Mean Square).(3) In the aspect of experiment research, a series of experiments have been carried out using ball-end mills to get milling force data. By comparison with the predicted milling force, it is shown that the simulation errors is small, which proves the correctness of the model.The work in this dissertation will establish a solid foundation for improving process modeling in the Virtual Manufacturing theory , for improving the stability and the security and machining quality in the milling process , and for developing the practical physicalsimulation system of milling process.