Numerical Simulation And Analysis For Machined Surface Topography In Milling Process And Form Error In Face Milling Process

Milling is a very common manufacturing process, which is widely used in a variety of industries, especially in aerospace and automobile industries. In order to reduce the cost and time, it is indispensable to develop the research activities on the milling process simulation. Based on the fundamental principle of the cutting process, efforts of this paper are focused on the simulation technology of surface topography in the milling process and form error in the face milling process, respectively.Simulating machined surface topography is very critical since it affects directly the surface quality, especially the surface roughness. In addition to this, simulation results will be used as basic data when process parameters are optimized. In this work, we formulate firstly the parametric equation of the cutting edge, whose trajectory equation relative to the workpiece is then generated through a series of coordinate transformations. Based on the trajectory equation and the geometrical characteristics of the milling process, a new method is developed for the prediction of the topography of the generated surface. The advantage of this method lies in that, on one hand, it is unnecessary to discretize the cutting edge and mesh the workpiece, and on the other hand, the topography values at any points on the surface of the workpiece can be calculated with the consideration of the cutter runout. Concretely, the surface topography of both end milling and ball-end milling processes is simulated successfully by this method. Numerical results indicate that the algorithm is general, efficient and of high precision.Besides, with the development of manufacturing technology, improving the machining accuracy is more and more required. To this end, the form errors must be evaluated and controlled strictly by selecting appropriate values for the process parameters. In this paper, an improved rigid cutting force model is established for face milling process. A study is made about the problems of multiblade cutter and multiple tool-passes. Numerical simulations are carried out by transform the continuous cutting process into a discrete one. Hence, the corresponding cutting load, which is continuous, is sequentially applied in a discrete form onto the finite element nodes of the machining surface of the workpiece when the latter are being cut. An algorithm is developed to determine each load case related to the node being cut. To improve the efficiency of computing form errors, a super-element (SE) technique of finite element method is applied to predict the deformation of the workpiece because of numerousnodes and load cases. With this technique, Resolution requirements, including CPU time, memory and disk space, are dramatically reduced so that large industrial applications can be solved.This work is significant to help the process engineers to select appropriate values for the process parameters at the process planning stage. Using these technologies, the manufacturing cost can be reduced and design cycle can be shortened. The simulation technologies have potential applicability to make manufacturing industries beneficial.