Research On Milling Simulation Of Thin-walled Parts And Secondary Development Of Its Platform

In recent years,with the continuous deve lopment of china's aviation industry,the requirements for the quality of aerospace structural parts have become higher.Thin-walled parts can be widely used since they can achieve the goals of reducing the weight of aerial structural parts and increasing their specific strength.The thin-walled parts are prone to machining deformation during processing and difficult to control the accuracy of machining because their low relative rigidity and poor processing ability.Therefore,the study of thin-walled parts' deformation law and proposing corresponding measures to reduce their processing distortions are of great significance to our country's aviation industry.This paper firstly describes the research status of cutting force prediction,deformation prediction of thin-walled parts and control measures in china and overseas.Then based on these previous research,this paper adapts the methods such as theoretical analysis,finite element simulation,experimental verification and optimization analysis to do in-depth study of thin-walled parts' milling deformation.It aims to search for the optimal cutting parameters in the machining process,establish a cutting simulation platform and finally improve the the effectiveness of building model.The main research work is shown as follows:This paper does in-depth analysis of the key technology in the finite element cutting simulation process,then provides detailed description of the specific aspects in accordance with the cutting model in this paper and uses it in the finite element simulation model based on full analysis of the variable thickness problem in the milling process.A three-dimensional oblique cutting finite element simulation model has been established for aerospace aluminum alloy(7050-T7451)to study the chip morphology,temperature,tension's distribution of rigid and non-rigid cutting tools during the cutting process separately.This paper focuses on the analysis the changing of cutting force during the processing and verifies the accuracy of cutting force model through cutting force prediction experiments.The three-dimensional thin-walled part milling simulation model has been established by finite element software ABAQ US based on the theory of machining deformation of thin-walled part and the thermo-mechanical coupling elasto-mechanical theory.It aims to analyze the tension and temperature distribution during the machining process.It focuses on the analysis of processing deformation in the process and uses the test method to verify the accuracy of processing deformation prediction model.The deformation prediction model has been established through BP neural network based on thin-walled parts milling simulation model.The nonlinear mapping relationship between cutting parameters and machining deformation has been obtained as well.Moreover,the cutting parameters have beenszj521 shy optimized by genetic algorithm.The single-objective optimization models which target machining deformation and double-objective optimization models that target both machining deformation and machining efficiency are finally established.Furthermore,the experiments in this article verifies that the optimized cutting parameters can reduce the machining distortion and improve the machining efficiency compared to the empirical parameters.The cutting simulation platform has been established by using Python language based on the kernel files.Then this paper describes the development process of the entire simulation platform in detail.Moreover,the development process of the kernel file is specifically explained by taking the tool parameterization process of two-dimensional oblique cutting as an example.In addition,the detailed development process of the GUI plug-in is described in detail by taking a two-dimensional oblique emulation plug-in as an example.This paper introduces the using methods of each module in entire simulation platform systematically and illustrates the parametric modeling process by using the example of three-dimensional oblique angles and three-dimensional thin-walled parts.This platform can automatically complete the pre-processing process of modeling based on input parameters.It has friendly interface,strong operability and can improve the modeling efficiency effectively.This platform has extremely high practical and reference value.