Study on the Effects of Pulsating Pressure on the Tube Hydroforming Process

• Main Authors: Quoc-Phong Bui, 裴國風
• Other Authors: Shyh-Chour Huang
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/08018585652023293771

碩士 === 國立高雄應用科技大學 === 機械與精密工程研究所 === 97 === The simulation of a hydroformed tube is performed in this study. The improvement in formability by the oscillation of internal pressure during the pulsating hydroforming of a tube is examined and the free bulging hydroforming of a tube under oscillation and constant internal pressure is performed. At a high constant pressure, a round bulge with local thinning is observed, whereas for a low constant pressure, wrinkling occurs. These defects from constant internal pressure are prevented by the oscillation of internal pressure in the pulsating hydroforming process. With pulsating hydroforming, a uniform expansion in the free bulging region is obtained, thus improving formability by preventing local thinning. The cause of uniform expansion in the pulsating hydroforming of a tube is interpreted from the variations of stress components.