Study On Numeircal Simulation Of Tube Hydroforming Process Of An Aluminum Alloy Sub-frame

As compared with the stamping and welding process, the tube hydroformingprocess exhibits several advantages, such as lower cost, improved strength andstiffness, part consolidation on assemblies, etc. Aluminum alloy becomes the rawmaterial as a result of the combination of the lightweight structure and the lightweightmaterial.Study on numerical simulation of tube hydroforming process of an aluminum alloysub-frame as a result of the combination of the hydroforming and aluminum alloy,study the forming law of aluminum alloy rectangular section tube and sub-frame andanalysis the reason of defect. Then put forward the reasonable measure to optimizethe forming quality.Firstly, the mechanism of how to improve the formability of the aluminum underthe high temperature condition is studied, then the Fields Backofen law is adopted tocharacterize the material behavior: C n mThe forming limit under differenttemperature based on the M-K theory and Barlar’s YLD2000material model isadopted as the failure criteria, and the best temperature is selected as the formingtemperature.Through the analysis of variety shape section of the bending axis, we can obtainthat the variety shape include quadrilateral, polygon, ellipse and irregular section, etc.All sections can be classified as especial section which consist of the straight edge andthe fillet between straight edges generally. Therefore, this paper uses finite elementsimulation software DYNAFORM to conduct numerical simulation which cananalysis the flow of material and the thickness of section in the process ofhydroforming. And study the influence between the factors which include the friction,radius of corner and loading paths and the distribution of thickness.Through the analysis of the strength, stiffness, the install location and the hydroforming process requirement of the sub-frame, the geometry of the sub-frame isdeveloped.Finally this paper uses finite element simulation software to analyse the tubehydroforming process of an aluminum alloy sub-frame, which include the process ofrotary bending, stamp forming as well as tube hydroforming. Analyse the reason offorming defect, and then through modify the geometry of sub-frame and the die ofstamp forming to obtain the aluminum alloy sub-frame which has the desiredformability.The study in this paper provide experience on the tube hydroforming of aluminumalloy bending axis profiled section tube, which includes the reason of defect and theenactment of process.