Cutting Deformation Simulation Analysis And Process Optimization Of Aero-engine Combustor Casing

Combustor casing is an important part of aeroengine,which is mostly made of hightemperature alloys,and widely used in thin-walled structures.The thin-walled structures often have problems such as poor rigidity,difficult material processing,and severe processing deformation,which restrict the manufacture of engines.This research is based on finite element simulation to study the cutting force and machining deformation in the turning of thin-walled parts,and analyze and optimize the processing parameters,which has a guiding significance for actual production.The cutting force simulation of the GH4169 material under the actual turning processing condition of the casing is carried out,and the influence of different process parameters on the cutting force is analyzed.The research object of this thesis is a certain type of aero-engine combustor casing,which is made of GH4169 nickel-based high-temperature alloys.By considering the actual cutting state and processing parameters,two types of Advant Edge 3D turning finite element models of Nose turning and OD turning are established respectively.The two three-dimensional turning cutting force simulation results are compared and analyzed,and the three-direction cutting force error of the two simulation results is about 10.5%,which verifies the validity of simulation results.Based on the cutting force simulation results at different levels,the process parameters are analyzed for the feed,cutting speed,cutting depth and main cutting angle.The results show that the cutting force increases significantly with the increase of feed and cutting depth,decreases first,then gradually stabilizes with the increase of cutting speed,and hardly changes with the change of main cutting angle.The finite element simulation of the surface error in the machining of the casing shell surface is carried out,and the machining process parameters are optimized with the surface error as the goal.A 3D Solidworks model of casing shell is built,and the Hyper Mesh hexahedron meshing is performed on it.Based on this,an Abaqus finite element model of surface error of the casing shell is established.Based on Python,the Abaqus finite element model is redeveloped and parameterized,so as to get the surface error of the casing shell surface at different positions.The results show that the surface error is in the range of 0.01～0.02 mm.The surface error increases first and then decreases,which is related to the rigidity of the casing shell surface.Through the modeling of cutting state,the orthogonal simulation experiment of feed and cutting speed,the different machining parameters are optimized in order to minimize the maximum surface error.The results show that it is more appropriate to select the processing parameters of "small feed and large cutting speed".The machining measurement experiment and tool wear observation experiment are carried out for the turning process of the casing shell.The technological process of the turning process of the casing shell is introduced,and actual machining experiment is performed of the casing shell.The wall thickness and bottom roundness of the workpiece surface are measured by threecoordinate machine offline.The results show that the wall thickness machining error gradually increases with the turning,which is related to the surface error and tool wear,bottom roundness values changes irregularly.The tool flank and the tool nose arc wear experiment are carried out.The results show that in the actual machining,only the tool nose arc on the side of the secondary cutting edge is used for turning of the workpiece.The tool nose arc wear is in the range of 0.01 ～ 0.02 mm,and the closer to the rake face,the greater the degree of wear.