Structural Optimization And Fatigue Simulation Analysis Of Aluminum Profile Extrusion Die

Aluminum profiles are widely used in construction,aerospace,rail vehicles,industrial machinery and other industries with their light weight,corrosion resistance,easy processing and good ductility.As people’s requirements for aluminum profile products become higher and higner,the requirements for molds are further improved.The extrusion mold continuously reciprocates the bar material in the environment of high temperature,high pressure and high friction,which often causes fatigue failure of a fragile structure of the extrusion mold and causes early failure of the mold.With the development of finite element technology,the use of finite element technology to simulate and improve extrusion molds has become the norm for mold optimization,which is of great significance for engineers to further optimize molds and verify them in actual production.The main research results of this paper are as follows:1.According to the theoretical analysis of profile extrusion and the structural design elements of planar flow shunt die,representative square tube hollow aluminum profile extrusion molds were designed,and flow field simulation and mold deformation analysis were carried out on them.The results of the flow field simulation are in line with the theoretical analysis and the quality of the obtained profiles is qualified.2.In the deformation analysis results of the mold,the stress distribution results of the square tube mold show that there is stress concentration at the weak shunt bridge and the mold core structure,and the stress amplitude is close to the yield strength of the material,which is consistent with the structure where fatigue cracks occur in the extrusion mold in actual production.3.According to the stress distribution results of square tube mold,three optimization schemes for extrusion mold are proposed.The first is to change the structure at the inlet of the original upper mold metal blank into a butterfly bridge structure and sink the bridge,which reduces the stress amplitude of the extrusion die by 10.3%;The second is the shunt bridge sinking treatment of the outlet surface of the upper mold,although it does not reduce the stress amplitude of the mold,but changes the position of the stress concentration,which still has reference value;The third is the optimization of the upper mold topology of the pipe mold,which not only reduces the stress amplitude of the extrusion mold by 14.9%,but also changes the position of the stress concentration.4.Based on the metal fatigue analysis method and fatigue damage accumulation theory,combined with the stress distribution results of the square tube mold,the load spectrum at the danger point and the S-N curve of the mold material were obtained,and the fatigue life analysis software Hyper Life was used to analyze the fatigue life of the upper mold where the danger point of the tube mold was located,and the position of the maximum fatigue damage and the minimum cycle life obtained was consistent with the position of the mold stress amplitude,of which the maximum fatigue damage was 2.840×10^-3and the minimum cycle fatigue life was 352 times.5.The fatigue analysis of the three optimized molds was carried out and the results of the square tube mold were compared.Among them,the fatigue life of the mold optimized by the upper die surface structure is improved by 11.6%compared with the original mold.The shunt bridge optimization mold failed to improve fatigue life despite changing the position of the maximum damage;The fatigue life of the topology-optimized mold is increased by 25%compared to the original mold.