Research On Key Parameters Of Tube Hydroforming Based On Numerical Simulation

There are many factors affecting the forming quality of tube hydroforming(THF)process,which lead to various defects of the forming parts.In order to improve the quality of the forming parts,it is necessary to determine reasonable process parameters in actual processing.Aiming at the axially bulging of low carbon steel pipe and the hydroforming of stainless steel pipe joints,the following research work had been carried out:1.Aiming at the axial bulging of low carbon steel tube,combined with the mechanical analysis and plastic deformation theory of tube hydroforming,the axial bulging of tube was studied by numerical simulation method.The influencing factors of bulging process were studied by controlling variables method,and the cause of wall thickness change and defects were analyzed from the point of view of stress and strain.2.Aiming at the defects of tube hydroforming and die for stainless steel joint,the die and clamping press were designed,and the reasonable die sizes were determined.The strength and deformation analysis of horizontal press and clamping press were carried out in ABAQUS,and the stress and deformation were controlled within a reasonable range to ensure that the forming parts could meet the accuracy requirements.At the same time,the influence of different clamping modes on die deformation was studied,and the hydraulic system schematic diagram of forming process was designed.3.The numerical simulation of hydroforming of 304 stainless steel joints was carried out in Dynaform 5.9.The effects of model parameters and process parameters such as shaping pressure,axial feed speed,friction coefficient and blank length on forming were analyzed.The quality of forming was judged according to the thinning rate of bulging zone and the precision of forming parts.The reasonable technological parameters are determined and explained from the angle of stress and strain,which can provide reference for the forming of expandable tube parts.Compared with the experimental data,it is found that the numerical simulation results have reference value.