Study On Error Prediction For Thin-walled Workpiece Milling Process And Developing Technology Of Fast Milling Simulating Platform

The characteristics of aeronautical thin-walled parts are general as follows:complex structure, thin-walled, variable thickness, many surface and curve structures,high reconciliation precision, etc. It is hard to control precision as it s easily deformedin machining process. Therefore, for some types of thin-walled workpiece, themachining process is simulated by finite element analysis software, some optimizedtechniques are summarized, and the secondary development is studied in improvingthe efficiency of the simulation. Those techniques have important theoretical value inimproving the machining accuracy.In this paper, on the basis of researches of thin-walled workpiece processingsimulation and secondary development techniques at home and abroad, the procedureof simulating the milling process of aero aluminum alloy7050-T7451cantilever slabthin-walled workpiece with thermal mechanically coupled analytical method issystemically studied, and simulating the processes of single-frame and multi-framethin-walled workpiece are researched based on previous research results. Finally, acustomized application is developed by Python programming language, thisapplication is used to parametric modeling. The specific research works are asfollows:Milling mechanism, cause and distributing area of cutting temperature arestudied, moreover, mathematical model of heat generation in thermal mechanicallycoupled model is established. In addition, some key techniques of simulation arestudied, such as setting of material property, Johnson-Cook constitutive model,contact settings of tool and workpiece, separation criterion of tool and chip and so on.The procedure of simulating the milling process of aero aluminum alloy7050-T7451cantilever slab thin-walled workpiece by means of Dynamic，Temp-disp，Explicit analytical type is systemically studied, and some simulatingresults are obtained, such as cutting force, residual stress, cutting temperature,processing deformation and so on. By means of comparing the results of simulationwith experiment, the accuracy of simulation result is proved sufficiently. It s thefoundation of following study on frame-type thin-walled workpiece process. Four different machining paths are adopted in simulating the milling process ofsingle-frame thin-walled workpiece, and the machining strategy is optimized bymeans of comparing the simulating results. Initial residual stress is loaded formulti-frame thin-walled workpiece, and "element birth and death" technique isadopted to achieve the selective removing of elements, therefore, the deformationrules of multi-frame thin-walled workpiece are obtained too.In order to achieve rapid parametric modeling for simulating milling process ofthin-walled workpiece, a customized application which named AeroCAE is developedby Python programming language. By means of parametric designing for FEA model,programming method is confirmed, and ABAQUS GUI graphical user interface andplug-ins for resulting output are established. The program can complete thepre-processing procedure automatically according to the inputted parameters, and theprogram interface is easy to operate and has important propagable value.