Study On Simulation Of Bulging-pressing Torsion Beam

Torsion beam is the core component of torsion beam rear suspension which is widely used in A and A0 class vehicles. The utilizing of bulging-pressing process can improve the performance of parts and reduce pressure compared to hydroforming technology. The reduction of pressure can lead to reduced cost and lower tonnage of manufacturing facility. The forming parameters match has great influence on forming quality, so it is necessary to research bulging-pressing torsion beam.The torsion beam of economy car is taken as research object, and the method of numerical simulation is used to research hydroforming and bulging-pressing process.Firstly, the hydroforming process of torsion beam is simulated. Through simulation, the main defects of hydroforming torsion beam are that the forming pressure is too high, the forming precision is low, and so on.Secondly, the finite element model of torsion beam is built. The bulging-pressing process of torsion beam is simulated. Through the comparison of simulation results of hydroforming and bulging-pressing torsion beam, it can be proved that bulging-pressing process can decrease the forming pressure and improve the quality of torsion beam.Then, the influence rules of blank diameter, hydraulic loading way, axial feeding and friction coefficient to forming quality are researched with controlling variables method. The ranges of pressure applying moment, forming pressure and friction coefficient are determined when they are regarded as the design variables of parameter optimization.Finally, the uniform experimental design method and response surface methodology are used to optimize the forming parameters that obviously influence the forming quality. In order to lower forming pressure and improve forming quality, fitting program and optimization program are used in this process.The defects appeared in bulging-pressing process are analyzed in this paper and the uneven thickness distribution is reduced by optimizing forming parameters. The optimized forming pressure is 21% of hydroforming pressure.