Experimental investigation and Numerical simulation of bending parameters on the spring back of the tube in the rotational bending process

Articles in Press

Document Type : Original Article

Authors

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

¹ Department of mechanical engineering, Semnan university

² Faculty of Mechanical Engineering, Babol Noshirvani university of technology

³ Faculty of Mechanical Engineering

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

10.22067/jacsm.2023.84485.1204

Abstract

Tube bending with a critical bending ratio necessitates the exploration of new bending methods. This research introduces a novel approach to rotational bending using a variable curvature bending die. Unlike conventional techniques that employ fixed-radius bending for hollow tubes with a round cross-section, this method gradually transitions the shape from a large radius to a small radius. To determine the curvature of the bending die, we employ an involute curve as the geometric equation governing the variable curvature of the bending die. With the advancement of tube hydroforming, pressurized fluid is employed instead of a mandrel in the rotational bending process. To investigate this, a thin-walled aluminum tube composed of 6063 alloys (with a D/t ratio of 13/88) is prepared and subjected to rotational tensile bending at critical bending radius ratios of D1, D1.6, and variable curvature, all at a 90-degree angle. Both simulation and experimental tests are utilized to analyze the impact of internal fluid pressure and bending die curvature on tube springback. The results demonstrate that, under constant pressure conditions, the use of a variable-radius bending die results in reduced springback compared to a fixed-radius bending die. Furthermore, the effect of internal pressure on the springback of the bent tube is found to be negligible.

Keywords

• Bending
• Variable radius die
• Fluid hydroforming pressure
• Tube spring back

Main Subjects

• Forming

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