Research On Techniques Of Modeling And Analysis Accelerating In Virtual Machining Process

VMP (Virtual Machining Process) is a kind of virtual realization of machining process in computer based on a comprehensive model, which takes account of geometric parameter of part, material property, cutting condition and physical process of cutting. It is expected to analyze the effect of geometric and physical aspects on cutting process, so as to predict the machined result, evaluate machinability of part and optimize machining parameter. It is an intuitional, efficient and economic approach.In this dissertation, which concentrates on the virtual machining process of the NC end milling of thin-walled workpiece, the relative techniques of virtual machining are reviewed. Then three themes are induced, which constitute the main research contents of this dissertation. They are as following: geometric models in NC simulation are not suitable for virtual machining process, there isn't suitable mechanics model to the machining process of flexible workpiece, and it is impractical to analyze deformation using FEA (Finite Element Analysis) totally in the whole virtual machining process for its low efficiency.According to the requirement analysis of virtual machining technology, a new architecture is proposed to provide a framework for the development of software and the research of key techniques. These key techniques can be classified to modeling technique and analysis accelerating technique.Modeling is the foundation of deformation analysis. In this dissertation, three models are studied. They are workpiece model which meet the requirement of virtual machining process, fixture model which is used to prescribe the boundary conditions for deformation analysis, and mechanics model of cutting process of flexible workpiece which is apply to describe the relationship of cutter movement, actual cutting quantity, cutting force distributing and workpiece deflection.Furthermore, the analytical (semi-analytical) algorithms are studied to calculate deformation rapidly for the thin-walled structures, which frequently appeared in end milling. Then a library of typical thin-walled components with their deformation algorithms is established to support the analysis accelerating technique. The deformation at key position is calibrated to compensate the inaccuracy of the rapid analytical algorithms in the library.