Study On Technology Of Physical Simulation For Virtual Manufacturing

An ever-increasing emphasis is being placed on market demand and fierce global industrial competition for manufacturing enterprise to survive and develop, and with the rapid technology advance in computer, virtual manufacturing is developed with the demands. Virtual machining process simulation is a key basic technology for virtual manufacturing, and takes an important place in it. It predicts and optimize effectively to all kinds of machining information in process system composed of machine tools, work piece, cutters and jig, so that it can help realizing the real machining process intelligently. Furthermore, it is a fundamental way to research deeply mechanism of the machining process. Virtual machining simulation is mainly consist of two parts, geometry simulation and physical simulation. The research on physical simulation is not under way deeply due to the sophistic mechanism of cutting and the difficulty in modeling. But the consideration of physical factors and prediction in cutting quality is necessary and important on virtual manufacturing research.In this thesis, the basic and cell technologies in physical simulation are researched. At first, the discuss of cutting force analysis modeling is made. Based on the orthogonal cutting, the oblique cutting force model is set up. With the dynamic cutting force coefficients (DCFCs) obtained form experiments, and the methods of the experiments combined with analysis, the end milling force and power model is set up and the simulation algorithm is given. The process system distortion affects the quality of machining, among which the dynamic character of machine tools is main part. By using the model analysis method and hammer test, the model parameters and model shapes are obtained based on the force and response signal processing. At the same time, the time series applying on modelanalysis is discussed. On the basis of cutting force model and vibration model of machine tools structure, the effect of the regenerative chatter on the stability of end milling is focused. The formula implying the index of machining stability is given and stability lobes of milling can be plotted. It helps predicting the level of machining and optimize process parameters.The sufficient research on the cell technology in physical simulation of virtual manufacturing is able to make it real application in production, predict the machining quality of products, shorten the time of developing new products, new equipments, decrease the costs of manufacturing. And the success of its application also helps making the manufacturing technology go out the narrow scope and enter the stage of prediction all-round.