Deformation Prediction And Process Analysis For Titanium Alloy Thin-walleded Workpiece

With the rapid development of aerospace industry in our country, thin-walled titanium alloy partis widely used in aerospace manufacturing because of its excellent overall performance andconstruction features. However the titanium alloy is a kind of difficult processing metal, and thethin-walled titanium alloy parts have small stiffness. Under the influence of cutting force, clampingforce and residual stress the defomation is prone to come into being in the maching processes,whichwill have great impact on the machining precision and its usability. The analysis and prediction of themachining deformation has an important significance. In this dissertation, my research mainlyinvolves the processing technology, cutting force modeling and deformation prediction of thin-walledtitanium alloy parts. The works mainly include:1. In consideration of the material feature and structural feature of linkage ring, the processroute is studied and the manufacturing process is determined,in which the machining method andlocating datum are involved. According to the original process route the experiment of the cutting iscarried out. Based on the problems which are found in the test, the process route is improved, andthen the method of Finite Element Analysis(FEA) is introduced into process route to conduct themachining deformation prediction of linkage ring.2. According to the milling force empirical model, the orthogonal test of the milling oftitanium alloy is designed, and the regression coefficient of the equation of linear regression isobtained with the least squares theory. Based on the exponent of every influencing factor achieved inthe empirical formula, the empirical formula of milling titanium alloy could be established andvalidation of significance testing and trial.3. In terms of the problems presented in the process analysis, aiming at simplified linkage ringstructure, the deformation model of thin-walled titanium alloy parts in the machining and cutting offprocesses is established. A lot of analysis is performed with respect to the geometric modeling, modeldiscretization, material definition, load application, boundary definition, material removal, stratifiedmilling, constraint conversion, the superposition of workpiece deformation and so on, and thenforecasting the deformation of simplified linkage ring during the process of machining and cutting off.At last the validation experiment is carried out by5-axis machining center.4. Customized development is conducted by the script language of ABAQUS, which canintegrate the function of machining deformation prediction, cutting-off deformation forecasting, tool deformation prediction and initial residual stress field analysis into the finite element simulationplatform, and realize rapid simulation analysis of typical thin-walled titanium alloy parts.