Research On Deformation Control Of Milling Of Thin-walled Structural Parts Of Integral Box

With the design concept of aerospace products updating, a lot of thin wall structure applied in aerospace products. A whole box of thin-walled structures, shape of the structure is complex, the overall rigidity is poor, easy to process deformation, dimensional stability is difficult to control. It is very difficult to simulate the NC machining deformation and experimental research. Has become a constraint to the national defense weapons equipment and the rocket manufacturing outstanding problems. This topic, starting from the main source of influencing the machining deformation, and a whole box of milling thin-walled structural deformation prediction and control are deeply studied, and proposed to optimize the technological process, the greatest degree of control the deformation of workpiece, to improve the machining accuracy.Firstly, the method of measuring the residual stress in the aluminum alloy sheet is studied, and find a suitable for residual stress measurement methods. Theoretical formula and experimental peeling method applied for the material internal residual stress distribution and residual stress value in each layer of material. On the basis of the finite element theory,studying the key technology of finite element simulation of milling, making the milling force measurement test and establishing the milling finite element model, meshing and setting boundary conditions for the model. Through the finite element method of the birth and death unit technology simulation milling, and verify the correctness of the model by experiment.Secondly, the simulation and control study on the several common tool paths. The effect of the tool path on the residual stress distribution and deformation is analyzed, and obtaining the tool path that can effectively control the deformation. The simulation and control study on the different number of platens and clamping position, and obtaining a clamping scheme which can effectively control the deformation. The simulation and control study on the milling parameters, analyzing the stress distribution and deformation of the workpiece under different milling depth, milling width, feed rate and milling speed. The orthogonal test of each milling parameter group was carried out to study the relationship between the different milling parameters and the influence of the interaction between the parameters on the machining deformation. The optimal combination of parameters to control the deformation of the workpiece.