Research On Ball End Milling Force Simulation And Experiment Based On Deformation In Milling Process Of Thin-Walled Part

Thin-walled parts has been widely used in aerospace and aviation and other fields with its advantages of light weight and high relative strength.However,because of low rigidity of thin-walled parts it will be deformed in milling process which lead to the decrease of the machining accuracy and surface quality,severe cases may cause parts scrapped.Therefore,it is really need to study the relationship between milling force and instantaneous deformation in milling process in order to control the deformation of thin-walled parts.In order to establish the peripheral milling force theory model of thin-walled parts,firstly,establish the peripheral milling force theory model which without considering the deformation of the workpiece.The model is composed of ball end milling cutter line geometry model,instantaneous undeformed chip thickness and accurate cutting angle range.Based on the identification of milling force coefficients,use the milling force program which have already established to study the milling force changes under different milling machining parameters.Secondly,established the finite element prediction model of aluminum alloy thin-walled parts of freedom ends,fixed ends and impeller blade respectively.Because the milling force is the main factor causing deflection in the machining process,therefore,the actual situation can be appropriately simplified in order to make the finite element analysis easier,such as: visual fixture systems,tools,etc.as the rigid body,ignoring tool wear and clamping error;workpiece material is linear elastic material and its physical properties remain unchanged in the milling process;ignoring the workpiece whole stiffness changes in the material removal process;milling force is equivalent to moving concentrated load loaded onto the corresponding node of cutting region;ignoring the plastic deformation of workpiece etc.Based on the above assumption,use the finite element analysis software to analysis the thin-walled parts of freedom ends,fixed ends and impeller blade respectively,summarize the deformation regularity.Finally,with aluminum alloy thin-walled parts of freedom ends and fixed ends as an example,amend the theoretical model in order to establish a more perfect thin-walled peripheral milling force model based on the milling force model without considering the deformation of workpiece and deformation regularity of aluminum thin-walled parts in the milling process,amended milling force model is verified by the experiment method.Sum up,the thin-walled milling force theoretical model established in this paper can effectively predict changes in peripheral milling force process,provide a theoretical basis for the optimization of process parameters for thin-walled parts and improve the machining accuracy and surface quality.