Modares Mechanical Engineering

Modares Mechanical Engineering

Numerical And Experimental Investigation Of Twisting Defect Of Symmetrical Channel Section With Asymmetrical Holes Formed By Cold Roll Forming

Document Type : Original Research

Authors
1 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran.
2 Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, IR Iran.
3 Department of Mechanical Engineering,Technical and Vocational University (TVU) , Tehran, Iran.
4 Department of Mechanical Engineering - Manufacturing and Production, Kashan University, Kashan, Iran.
Abstract
The roll forming of an asymmetrical channel section is associated with a twisting defect, but this defect also occurs in a symmetrical section whose holes are asymmetrical. Therefore, first, a finite element model was presented to investigate the process. By designing the full factorial method, the important factors affecting the twisting defect and the effect of each during the cold roll forming process have been investigated. In the end, it was concluded that the thickness of the sheet and the diameter of the holes are the most important factors affecting the twisting defect. It was concluded that the greater the difference in the diameter of the holes on both sides of the channel, the higher the amount of twisting defect. For the forming angle of 45 degrees, by increasing the thickness of the sheet from 2 mm to 3 mm, the twist angle of the piece increased from 1.5 degrees to 2.5 degrees. According to the behavior of the metal, a series of experimental tests were designed and the effect of the hole diameter factor on this defect was determined. Appropriate matching of experimental and numerical results indicates reliable and verifiable numerical results.
Keywords

Subjects


[1] Halmos GT.Roll forming handbook. CRC Press. 2005;153.
[2] Bhattacharyya D, Smith P, Thadakamalla S. The prediction of deformation lenght in cold roll forming. J. Mech. Work. Technol. 1984; 9:181–191.
[3] Watar H, Ona H. Cold roll forming of small-diameter pipes with pre-notch. J.Mater. Process Technol. 2001;119:122-126.
[4] Weissa M, Abeyrathnaa B, Rolfeb B. Effect of coil set on shape defects in roll forming steel strip. Journal Of Manufacturing Processes. 2017;25:8–15.
[5] Tajik Y, Moslemi naeini H, Azizi tafti R, Shirani bidabadi B. A strategy to reduce the twist defect in roll formed asymmetrical-channel sections. Thin-Walled Structures. 2018;130:395–404.
[6] Shirani bidabadi B, Moslemi naeini H, Azizi tafti R, Barghikar H. Experimental study of bowing defects in pre-notched channel section products in the cold roll forming process. Springer-Verlag London, 2016.