Design of tube Hydroforming system with the Die Ultrasonic Vibration

Abstract

In tube hydroforming process, due to friction condition, uniform wall thickness, as well as sharp corners may not be achieved. Use of ultrasonic vibration can improve the contact conditions at the tube-die interface. The current work studies the effect of applying ultrasonic vibration on wall thickness and corner filling of hydroformed tubes. By comparing the FEM models of tubes in two cases of with vibration and without vibration, it is possible to investigate the effects of vibration on wall thickness and corner filling. In addition, the finite element analysis, as the modal and harmonic analysis, are used to design a set of ultrasonic tube hydroforming. Annealed copper tubes are used for the experimental tests. The simple mechanism introduced in this paper is used to form the tube, by which the final piece is produced with lower costs and without any need to hydroforming machine. The results indicate superimposing ultrasonic vibrations to the process will increase corner filling ratio of the tube significantly, and more uniform tube wall thickness will be achieved.