Numerical simulation and experimental study on hydroforming of variable diameter tube

The forming accuracy of finite element simulation mainly depends on the accuracy of constitutive model. In order to solve the problems of complex hydroforming processes and low success rate of sample trial production, the method of improving the accuracy of numerical simulation and the control accuracy of experimental equipment was proposed to carry out the trial production of sample hydraulic forming of variable diameter tube. In this paper, starting from the study of the circumferential mechanical properties of the tube, the circumferential mechanical properties of the original tube blank are obtained by using the experimental device of tube end flaring, which is used for the numerical simulation study of variable diameter tube hydroforming, so as to improve the numerical simulation accuracy of the internal high pressure forming process. Then, in order to improve the axial feed control accuracy of the original equipment, a reduced-diameter tube hydroforming system based on servo-electric cylinder is built, and the corresponding experimental research is carried out. At the same time, through the hydroforming experiment of variable diameter tube, the thickness distribution results obtained by numerical simulation are compared with the experimental results to verify the correctness of the numerical simulation method and the established finite element model. Finally, the loading path is optimized by combining experiment and simulation, and it is verified by experiment. The experimental results show that by improving the accuracy of numerical simulation and the control accuracy of experimental equipment, the success rate of the trial production of variable diameter tube samples can be effectively improved and the trial production period can be shortened.