Bendability Analysis for Bending of C-Mn Steel Plates on Heavy Duty 3-Roller Bending Machine

Authors: Himanshu V. Gajjar, Anish H. Gandhi, Tanvir A Jafri, Harit K. Raval

Abstract:

Bendability is constrained by maximum top roller load imparting capacity of the machine. Maximum load is encountered during the edge pre-bending stage of roller bending. Capacity of 3-roller plate bending machine is specified by maximum thickness and minimum shell diameter combinations that can be pre-bend for given plate material of maximum width. Commercially available plate width or width of the plate that can be accommodated on machine decides the maximum rolling width. Original equipment manufacturers (OEM) provide the machine capacity chart based on reference material considering perfectly plastic material model. Reported work shows the bendability analysis of heavy duty 3-roller plate bending machine. The input variables for the industry are plate thickness, shell diameter and material property parameters, as it is fixed by the design. Analytical models of equivalent thickness, equivalent width and maximum width based on power law material model were derived to study the bendability. Equation of maximum width provides bendability for designed configuration i.e. material property, shell diameter and thickness combinations within the machine limitations. Equivalent thicknesses based on perfectly plastic and power law material model were compared for four different materials grades of C-Mn steel in order to predict the bend-ability. Effect of top roller offset on the bendability at maximum top roller load imparting capacity is reported.

Keywords: 3-Roller bending, Bendability, Equivalent thickness, Equivalent width, Maximum width.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1061408

References:

[1] M. B. Bassett, and W. Johnson, "The bending of plate using a three roll pyramid type plate bending machine," J. strain Analysis, vol. 1, no. 5, pp. 398, 1996.
[2] N. E. Hanson, and O. Jannerup, "Modeling of elastic plastic bending of beams using a roller bending machine," ASME Papers No. 78wa/Prod 6, 1979.
[3] M. Hua, D. H. Sansome, and K. Baines, "Mathematical modeling of the internal bending moment at the top roller contact in multipass four roll thin plate bending," J. mater. Process. Technol., vol. 52, pp. 425-459, 1995.
[4] M. Hua, K.Bainesb, and, I.M. Cole, "Continuious four roll plate bending: a production process for the manufacture of single seamed tubes of large and medium diameters," Int J. Mach.Tools Manuf., vol. 36, pp. 905-935, 1999.
[5] Weilong Hu, and Z.R. Wang, "Theoretical analysis and experimental study to support the development of a more valuable roll-bending process," Int J. Mach.Tools Manuf., vol. 41, pp. 731-747, 2001.
[6] V. Ramamurti, V. Ravi Sankar Rao and, N. S. Sriram, "Design aspects and parametric study of 3-roll heavy duty plate bending machines," J. mater. Process. Technol., vol. 32, pp. 585-598, 1992.
[7] J. L Dunkun. and Z. Marciniak, Mechanics of sheet metal forming, Adward Arnold Publication, 1992, pp. 68-77
[8] Process manual, maintenance manual, machine capacity chart and technical specification of rolling machine, M/s Larsem & Toubro ltd, Hazira, Surat, India.
[9] G. H. Ryder, Strength of Material, English language book society / Macmillan, 1969, pp. 71-85.
[10] A. I. Tselikov and V. V. Smirnov, Rolling Mills, Pergamon press, 1965.
[11] ASME sec II part A, Ferrous material specification, 2004 edition.