Improve the formability in tube hydroforming process using ultrasonic vibrations

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 radius 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 process. In addition، the finite element analysis، as the modal and harmonic analysis، are used to design a set of ultrasonic tube hydroforming. A simple mechanism introduced in this paper is used to form the tube. The results indicate superimposing ultrasonic vibrations to the process will improve formability and spring back of the، and more uniform tube wall thickness will be achieved.