Plastic Deformation and Stress Analysis on Hydro-pressing of Mild Steel Tube with Elliptical Section

doi:10.3901/JME.2017.18.035

Abstract

Abstract: Preforming is the key to the hydroforming process. The forming defects and thickness distribution are directly affected by the shape of the preform. A hydro-pressing forming method is proposed to solve the problems in conventional mechanical pressing process without internal pressure, such as dent defects and size uncontrollable. The stress analysis and experimental research are performed for the hydro-pressing process of mild steel tube with elliptical sections. The differences are compared between the hydro-pressing and the conventional mechanical pressing. The effects of supporting pressure and pressing displacement on section stress, wall thickness distribution and section shape are investigated. It is demonstrated that the equivalent stress distribution of pressing tube was improved by hydro-pressing process. The greater the supporting pressure, the more uniform the equivalent stress distribution. Compared with conventional mechanical pressing, the thickness variation of the elliptical section is unobvious during hydro-pressing process. The maximum thinning is located in the middle region of the straight wall. When the supporting pressure is 15 MPa, the maximum thinning is only 2%. Dent defects located in the straight wall of the tube is decreasing with the increasing of supporting pressure.

Key words: hydroforming process, hydro-pressing, preforming, tube mechanical pressing, wall thickness distribution

CLC Number:

TG394

ZHANG Xinlong, HE Jiuqiang, HAN Cong, YUAN Shijian. Plastic Deformation and Stress Analysis on Hydro-pressing of Mild Steel Tube with Elliptical Section[J]. Journal of Mechanical Engineering, 2017, 53(18): 35-41.

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