Research On Modeling And Simulation Of Surface Topography In NC Milling Process

In this paper, theoretical analysis and experiment method have been used to study the tool wearand machining workpiece surface topography considering tool wear in cemented carbide ball-endmilling of difficult-to-cut materials. The main achievements are as follows:1. Tool wear model was established based on LS-SVM with the tool wear by using on-line toolwear monitoring based on machine vision. In light of the change in tool wear resulting from thechange in cutting conditions and environment, Kalman filter was employed to build dynamic wearmodel, which consider the actual tool wear and updated the prediction of wear model. In order tovalidate the proposed scheme, a series of orthogonal machining experiments were designed andfinished by using milling tools.2. The equations of cutting edges of ball-end mill are given by employing analytic geometryprinciples. Then the locus equation of ball-end cutting edge relativing to the milling workpiece wasestablished by combining with the relative motion of the cutting tool on the workpiece. A new modelof surface topography was designed to obtain the locus by considering the influence of tool wear, toolangle and the spindle eccentricity.3. Cutting edge is divided into a series of cutting points according the maximum position angle inmilling process, and then the miiling workpart is divided into a series of cutting units. An algorithm isproposed to simulate generation of surface profile in milling operation based on the establishedsurface topography model and a update method of surface toography according to build verticaltangent plane to the cutting point to obtain a new surface mesh point after cutting. Finally the onlinesimulation of surface topography of milling workpiece was established by considering the tool wearobtaining by tool wear monitor system in milling process.4. A series of machining experiments had been designed by using ball-end cemented carbidescutting tool milling stainless steel0Cr17Ni12Mo2to validate the proposed surface texture scheme.Comparing the simulation results and experimental results validated the correctness of the surfacetopography model and the effectiveness of the simulation system.