Study On Numerical Simulation Of Door Post Aluminum Profiles Extrusion Process And Structure Optimization Of Extrusion Die

With high specific strength, corrosion resistance, great surface treatment, low density, high recycling and reusing property, thermal conductivity, the aluminum alloy are widely used in various areas. Previously, the aluminum extrusion die is designed with traditional theory. With the aluminum extrusion becoming large-scale, complex and precise, this pattern cannot meet the trends. And now the numerical simulation method has been used to study the extrusion process and optimize the structure of die. It is very popular.Door post is widely used in the window frame and door frame. In this paper, the finite element software Hyper Xtrude is adopted to study the steady extrusion process of plane distribution composite die. The simulation results show that the exit velocity of profile is uniform and mold bridge root generates stress concentration. The average maximum equivalent stress is 1543 Mpa, more than the yield strength of H13 steel. In the actual extrusion, the mold bridge root crack and cause die failure. This result is consistent with the actual extrusion process. It means that the simulation is feasible and accurate. And the reason for bridge root cracking is analyzed. Because the dead zone of mandrel is too large, the extrusion breakthrough pressure is greater. And the bottom of bridge is made asymmetric, so the deformation on both sides of the bridge is not uniform and the stress difference appears. Thus, the stress concentration occurs at the root of the transition region, leading to bridge fracture failure.On account of the defect structure of the original mold, two optimized structures have been put forward to reduce the extrusion breakthrough pressure and mold stress. The one is to make the entrance of die subside, and the other one is butterfly bridge structure. The simulation for two methods has been done to do the structural analysis and evaluate optimization performance. Finally, based on the first method, the study has been done to analyze the effect of diverse extrusion speed on the process.By comparing the simulation results, we find that the optimization performance of first method is greater, which reduces the extrusion force by 5.5%.Besides, the average maximum stress of bridge roots decrease by 9.1% and the die cap maximum stress decrease by 20.7%. Meanwhile, with the extrusion speed increasing, the exit velocity of profiles SDV, extrusion pressure, mold deformation, mold stress, profile and mold temperature increase. Such mold structure is meaningful to improve die life.