Research On Control Method Of Wrinkling In Rubber Bladder Forming Of Shrink Flanging Part

In the aviation manufacturing industry,Frame Rib parts are difficult to form as a sort of sheet metal pieces.The traditional method is semi-manual operation of the pressure forming,it was replaced by Rubber bladder “one step” process.Wrinkling and Springback are the main defects in shrink flanging.Wrinkling is present in the part forming process,and Springback occurs after pressure unloading.It is obvious that no wrinkles is the premise to control Springback defect.It is the most important of controlling Wrinkle.In this text,A tensile strength test about formability parameters at the conditions of different aging time in as-quenched state of 2024 and 2A12 aluminum alloys make an analysis,which provides accurate material constitutive model for FEM of Rubber bladder “one step” forming and effective theoretical basis.The effective expansion of the blank is beneficial to improve the uniform distribution of stress and strain in sheet metal forming,control of wrinkling while increasing the forming limit.The raw blank shape is obtained by developing the blank expansion module of the CATIA platform using the rotary method based on the shrink flanging blank expansion formula.FEM has been used to simulate with the help of dynamic non-linear arithmetic and analyze the high pressure rubber forming process of part with flange bending.Analysis and forecast wrinkling.First research the influence of mesh generation and friction coefficient and Loading rate and to the shrink flanging part.Then puts emphasis on the analysis the influence of rubber constitutive model and rubber hardness on the forming wrinkles.By taking the side blank holder to control wrinkling,analysis the influence of four geometric parameters of side blank holder on the wrinkling.By using of orthogonal experiment method,define the optimal path and the influencing factors of primary and secondary order.The relationship of geometric parameters and wrinkling index is based on the response surface methodology.Then Genetic Algorithm is used to optimizing geometric parameters,the updated paremeters were used for FEM model and improve the model calculation quality.Through the further practical test.Verified the reliability and scientificity of the FEM.