Research On Prediction Of Deformation Due To Milling Process For Aircraft Monolithic Component Based On Relay Algorithm

In the process of milling,as the material is removed in a large proportion,the overall rigidity of the machined monolithic components is deteriorated,resulting in difficulties in the milling processing.Therefore,by using ABAQUS finite element simulation software to numerically simulate the milling process,this thesis analyzes the influence of multi-factors on the deformation of aircraft monolithic components from the perspective of prediction of the deformation.In this thesis,both domestic and international research achievements which have analyzed factors of deformation in the process of aircraft monolithic components are summarized.The thesis first selects the typical aviation structural parts by establishing finite element model to numerically simulate the whole process of the milling process.Then,the machining deformation of aircraft monolithic components is analyzed by considering the three factors of deformation— initial residual stress in the blank of the materials,combined effect of the initial residual stress and the cutting temperature,and coupling effect of the initial residual stress and the cutting force.The focus of this paper is to introduce relay algorithm and sub-model method in the simulation milling process.Relay algorithm is a reasonable method to optimize the simulation.As for the larger components,coarse and fine meshes are divided in a reasonable partition and regional fine meshes are calculated preferentially,while the rest of the meshes are coarsened.Thus,the simulated calculation of the entire parts are completed gradually.In this way,it is achievable to simulatedly calculate larger components and to ensure adequate accuracy requirements in the case of limited computer resources.After completing the simulation of large aircraft monolithic components based on the relay algorithm,sub-model method is used to further analyzes the needed parts when there is need for detailed simulation analysis and overall calculations have been completed.Finally,by combining the cases of aeronautical parts,the simulation of the initial residual stress in the processing of monolithic components is completed and the calculation of the stress under the initial residual stress and the temperature field is completed based on the relay algorithm.With reference to Chengdu monolithic components,rough machining are simulated by relay algorithm and the simulationresults are used as the global model of finish machining,then the coupling effect of residual stress and milling force in the finish machining of those components is completed by using the sub-model method.It is of important guiding significance to the actual milling process by using the finite element model calculation results to analyze the deformation regularity of monolithic components.