Papers by Keyword: Roll Bending

Abstract: High-strength steel is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel. Strip shape is an important factor affecting the strip quality significantly for the rolled products. Because of the complex influence factors of plate shape and profile, shape detection and control technology have not been solved, especially for high strength steel rolling. In this paper, a novel three dimensional finite element simulation of the strip shape and flatness of high strength steel has been proposed. The material constitutive model has been built up based on experimental results through the Gleeble 3800 Thermal Simulator under different temperatures and stain rates. The modelling of roll elastic deformation system, roll gap profile and edge drop has been set up systematically considering the influence of the work roll transverse shifting and roll bending. Results have shown that both higher bending force and more roll shifting will significantly reduce the strip crown, and obtain improved edge drop distribution as well. The proposed numerical model has been validated through hot rolling experiments in 4-high rolling mills.

Abstract: Roll bending is a useful technology for manufacturing a wide variety of products in small quantities. However, the roll bending of structural channels, which have a complicated sectional shape, causes irregular deformation. On the other hand, there are fewer reports on the bending of structural channels compared to those on the roll bending of sheet-metals. The purpose of this study is to clarify the deformation behavior in the roll bending of structural channels. The present paper reports on the results from a finite element analysis of the effects of the roller shape on the deformation behavior in the roll bending of structural channels.

Abstract: In this paper, an integrated rolls system deformation calculation model is established based on the influence function method combining with pass schedule calculation, rolls wear and roll thermal deformation calculation, and the corresponding calculation procedure has been developed. Then the influence of work roll bending, work roll shifting and intermediate roll bending on transverse distribution of strip thickness, strip crown, quadratic flatness, and quartic flatness are analyzed with the procedure. According to the analysis result, flatness control strategy of the single-stand reversing cold rolling mill is determined. The flatness control strategy will provide the basis for flatness control presetting of the mill. The practical application shows that the flatness control strategy is suitable for flatness control of the single-stand reversing cold rolling mill.

Abstract: Cylindrical components produced by mecano-welding process are widely used in industries. The mecano-welding process consists of a roll bending sub-process which can produce non-closed cylinders and a welding process which can seam gaps. This paper proposes a numerical model to simulate the process and to get better understanding of the process mechanism. Explicit and implicit solvers are applied to the numerical modeling by using LS-DYNA and ANSYS software. The numerical model can provide a useful tool for design and optimization of the mecano-welding process.

Abstract: In this paper, an analytical solution for the three-roll bending process of thin-plate was presented. Based on the theoretical analysis on continuously loading and unloading deformation of the plate during roll-bending, the curvature equations governing the bending behavior of thin-plate were set up and then solved by integration. Combing the solutions with the geometrical relationships in three-roll bender, the deflection and bending angles occurring during the steady continuous bending period were obtained by an iterative scheme. Numerical examples were given to illustrate the application of the solutions. The variation of the top roll’s position with the intended bend radius, the curvature and deflection distributions on bent plate were shown in graphically and discussed.

Abstract: The analytical solutions for the deformations of straight-ends in three-roll bending process of thin-plate were presented. Based on the theoretical analysis on the loading and unloading during roll-bending, the curvature equations governing the bending behavior of thin-plate were set up and then solved by integration. Numerical examples were given to illustrate the application of the solutions. The curvature and deflection distributions on straight-ends were shown in graphically and discussed.

Abstract: With the advantages such as light weight, high structure intensity and good rigidity, integral panel skins have been widely applied in aerospace industry. The forming process of mechanical milling-filling auxiliary roll bending and the incremental bending of integral panel skins were proposed based on the finite element method and the experiments technique. The research shows that the shapes of panel skins were binded by the ribs plastic deformation. The roll bending was suitable to the panel skins with the low ribs or the simple structure. The incremental forming was suitable to the panel skins with the high ribs or the involutes structure.