Experimental and Numerical Investigation of Pressure-Induced Changes in Tube Thickness Distribution and Cross-Section during Rotary Bending

Articles in Press

Document Type : Original Article

Authors

• Farzad Ahmadi khatir ¹
• Majid Elyasi ²
• Hossein Talebi-Ghadikolaee ³
• Vahid Modanloo ⁴

¹ Faculty of Mechanical Engineering, Semnan University, Semnan, Iran

² Faculty of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran

³ Faculty of Mechanical Engineering

⁴ Mechanical Engineering Department, Sirjan University of Technology, Kerman, Iran

10.22067/jacsm.2024.86421.1237

Abstract

Among the innovative techniques employed to achieve desired bends, rotational tensile bending has emerged as the most prevalent and controlled method for tube bending. This research focuses on the hydraulic rotational tensile bending of aluminum tubes made from alloy 6063. The primary objective is to examine the influence of the bending die type on the quality of the resulting bend, particularly in terms of thickness distribution and cross-sectional shape. The study involves two constant bend radius ratios as well as variable bending radii. The impact of internal fluid pressure on the quality of the bent tubes is investigated. The quality assessment criteria for the bent tubes include ovality and variations in tube thickness. The obtained results demonstrate that the highest level of ovality in the cross-section occurs during fixed-radius bending at an angle of 33 degrees, while variable-radius bending at an angle of 22.5 degrees exhibits maximum ovality. Furthermore, the findings from the thickness distribution analysis reveal that, under constant pressure conditions, the curvature of the bend radius significantly influences thickness distribution. By examining how the tube is formed in the process of rotational tensile bending of the tube with internal fluid pressure, it was observed that the maximum amount of ovality in the state without using internal fluid pressure in the bending ratio of 1, 1.6 and variable radius, 48.46%, 17.68% and 19.6% respectively. While at a pressure of 3.8 MPa, the maximum amount of ovality in the bending ratio 1.6 and variable radius is 10.82% and 11.22%, respectively.

Keywords

• Bending
• Hydroforming pressure
• Thickness distribution
• Tube bending simulation

Main Subjects

• Forming

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