3D Surface Topology Simulation Of Feed Direction Vibration Assisted Milling

With the development of science and technology, surface integrity becomes more and more important. Requirement for surface property is different according to the different applications. For example, in precision fit situation, small surface roughness is needed. However, surface roughness is large enough in friction drive situation. Cutting is the main machining method and the most of the time, surface property is ensured by cutting. As a result, new cutting methods are needed to be developed. Vibration assisted cutting can improve the cutting edge movement of traditional cutting, which can obtain special cutting surface. It becomes one of the most important issues in machining fields.The movement of vibration assisted milling is very complex, and the vibration parameters and cutting parameters can influence the surface morphology. Surface morphology can be changed through changing the process parameters which display the importance in studying this issue. Movement motion of cutting edge in vibration assisted milling is studied in this paper, and surface morphology simulation model is built to study the effect of process parameters on surface morphology.Two-dimensional movement motion of tool tip in feed-direction vibration assisted milling is established. A single cutting edge of the end milling cutter is studied, and the separation condition between single cutting edge tool and workpiece is derived. The influence of cutting parameters and vibration parameters on the cutting edge trajectory is studied by using the two dimensional kinematic equations of the two-edge cutter.Based on the shape of cutting edge, the simulation model of 3D (three-dimensional) surface topography was established. First, the cutting edge equation and coordinate system are established, and the motion equation of the cutting edge in workpiece coordinate system is obtained by means of the coordinate transformation. Secondly, Based on the discretization of workpiece, cutting edge and cutting processing time, the location points is determined by coordinate transformation. And thus 3D surface morphology simulation model is established in feed-direction vibration assisted milling. At last,3D surface morphology simulation model is achieved in software MATLAB. In order to make the model more convenient, an independent operation of the simulation interface GUI design of MATLAB is made.The accuracy of model is verified by comparison between simulation and experiment results. The simulated surface roughness is smaller than that of experiment surface roughness. What’s more, variation law of surface morphology in simulated situation is the same with that in experiment situation. It is indicated that the simulation model can predict the real surface morphology commendably.After validation of the program, effects of spindle speed, feed rate per tooth and amplitude on variation law of 3D surface morphology is studied through the simulation model. It can be concluded that when the ratio of the vibration frequency and the spindle rotating frequency is even, there’s no overlap between the microstructures formed by the two cutting edges. A ’wave structure’ is shaped. As the increase of spindle speed, the radius of curvature of surface vibration lines decreases. As the increase of feed rate per tooth, the number of’wave structures’ decreases. However, the scallop of’wave structure’ gets higher. When the ratio is odd, there’re overlaps between the microstructures. Bulge and pit are formed. As the increase of spindle speed, the number of microstructures decreases in same size area. As the increase of feed rate per tooth, the number of microstructures decreases in same size area. As the increase of amplitude, the overlapping width increases. When the vibration frequency and spindle speed are fixed, the cutting trajectory curvature increases with the increase of amplitude.