Finite Element Analysis And Parameter Optimization Of Milling Titanium Alloy Curved Thin-wall Bending Parts

Due to its high strength,light weight,high temperature resistance and other excellent characteristics,titanium alloy thin-walled structural components are increasingly used in aerospace,military equipment and other precision manufacturing industries,such as aircraft engine blades,skins,bosses,Ribs,side walls,webs,etc.However,due to the small overall rigidity and high material removal rate of such parts,it is difficult to process them.Factors such as cutting force,chip deformation,cutting chatter,and cutting temperature seriously affect the surface machining accuracy of the parts.Coupling action is prone to quality defects such as cracking,springback,wrinkling,and cross-sectional distortion.Therefore,based on theoretical modeling and finite element simulation,this paper has conducted an in-depth study on the cutting deformation of titanium alloy curved thin-walled parts based on the metal cutting mechanism.The specific research contents are as follows:(1)Introduce the basic properties and common processing methods of titanium alloy thinwalled parts,and analyze the main influencing factors and causes of its processing deformation.(2)Based on the basic theory of metal cutting and based on the basic theory of bending thin-walled parts,the theoretical model of bending deformation of curved thin-walled parts under normal load is established.(3)Ansys static analysis simulates the milling process of curved thin-walled parts,and determines the maximum deformation point in the circumferential direction of the workpiece during the milling process of curved thin-walled parts.It is also the cut-out point of one pass of the cutting process.The maximum deformation in the R direction is 3.13% of the wall thickness.Then the orthogonal test of 4 factors and 4 levels is used to determine the cutting parameter combination that minimizes the deformation of the maximum deformation point within a certain range.(4)Design a single factor test to study the influence of various cutting parameters on the deformation of the milling process of curved thin-walled parts within a certain range.The order of the influence of the three cutting factors on the deformation of the curved thin-walled parts is radial depth of cut,axis The depth of cut,feed per tooth,and milling speed,in which the axial depth of cut and feed per tooth have almost the same degree of influence on the machining deformation,the influence of the change in milling speed on the machining deformation in this range can be ignored.(5)Two kinds of auxiliary supporting models for milling of thin-walled curved parts were constructed,and the machining deformation under non-auxiliary support,cylindrical auxiliary support and pressing block auxiliary support were analyzed and compared,and the deformation of curved thin-walled parts under different pressing block pressures was analyzed and compared.A comparison was made.The result analysis shows that the deformation of the cylindrical auxiliary support is larger than that of the cylindrical support;when the support of the block is used,the deformation in the R direction is the smallest,which can better ensure the roughness of the part.In addition,the radial machining deformation of curved thin-walled parts with different numbers and positions of cylinders as auxiliary supports was studied.The results show that it is more reasonable to add a large number of supports on both sides of the curved thinwalled part,and add a small amount of support in the middle,which can effectively improve the stiffness of the part and reduce the processing deformation.(6)Carry out dynamic analysis on the curved thin-walled parts.Through the modal analysis of the TC4 curved thin-walled parts,determine its natural frequency and vibration mode,and then analyze the harmonic response of the TC4 curved thin-walled parts.The displacementfrequency response curve of the node confirms that the frequency when the tool and the workpiece are resonating is consistent with the natural frequency of the thin-walled bending member,and the peak displacement and response frequency of the node 15 are obtained.Finally,through the analysis of the second-order vibration mode,the position of adding auxiliary support is determined,and the natural frequency of bending thin-walled parts with and without auxiliary support is compared with No.15(X=-64,Y=0,Z=80)The displacement-frequency response curve of the node proves that adding an auxiliary support can increase the natural frequency of the thin-walled bending member,effectively suppress the deformation caused by resonance,and improve the machining accuracy of the workpiece.Through the above research work,it can provide a certain theoretical reference for the processing of curved thin-walled parts,and provide a basis for the deformation control of curved thin-walled parts.