Research On Simulation Technology In Optimization Machining Process Of Thin-walled Parts

Because of complex structure and low rigidity, thin-walled parts in aeronautic engineering are easy to be deformed when the clamping forces and cutting forces are employed. As a result, it is difficult to ensure the high machining accuracy of parts. Research on optimization technology of machining process of thin-walled parts by using finite element method (FEM) has important theoretical and practical value in improving machining accuracy.In this paper, optimization methods of improving machining accuracy of pint-sized/medium-sized thin-walled aeronautic parts, which include optimization method of fixturing, optimization method of cutting parameters and optimization method of active compensation path, are analyzed by integrating simulation and experimentation. The main work is as follows:Firstly, an optimization method of fixturing scheme of pint-sized/medium-sized thin-walled parts is researched. Mathematics model of optimizing fixturing aiming at minimizing form and position errors of important faces caused by fixturing deformations is founded. Key points and processes of optimizing fixturing with finite element analysis (FEA) software (ABAQUS) are studied.Secondly, an optimization method of cutting parameters of thin-walled part machining with optimum fixturing is researched. Dynamic simulation model which can predict deformations of thin-walled part in layered milling is established. With this model, the magnitudes and changing trend of machining deformations with different cutting parameters are analyzed and compared. The optimization method integrating genetic algorithm (GA) and finite element method (FEM) is used to optimize cutting parameters of thin-walled part.Thirdly, in order to further reduce machining error, an optimization method of active compensation path of thin-walled part is research based on optimum fixturing and optimum cutting parameters. Methods of full compensation and optimum compensation are presented according to theory of active path compensation. An optimization model of path compensation is established. Machining errors with compensation and without compensation computed by using dynamic simulation model are compared. The validities of FEA model and optimization model are demonstrated by comparing experimentation results and simulation results.Finally, in order to realize quick simulation of optimization machining process, a fast simulation platform integrating functions of fixture optimization, machining deformation prediction, cutting parameters optimization and active compensation path optimization is structured after in-depth studying methodology of further development in ABAQUS. Friendly interactive interface of parametric analysis is offered in the integrated platform.