三辊卷板机(纯英文).docx

Analytical and empirical modeling of top roller position for three-roller cylindrical bending of plates and its experimental verificationA.H. Gandhi, H.K. RavalAbstract：Reported work proposes an analytical and empirical model to estimate the top roller position explicitly as a function of desired (final) radius of curvature for three-roller cylindrical bending of plates, considering the contact point shift at the bottom roller plate interfaces. Effect of initial strain and change of material properties during deformation is neglected. Top roller positions for loaded radius of curvature are plotted for a certain set of data for center distance between bottom rollers and bottom roller radius. Applying the method of least square and method of differential correction to the generated data, a unified correlation is developed for the top roller position, which in turn is verified with the experiments, on a pyramid type three-roller plate-bending machine. Uncertainty analysis of the empirical correlation is reported using the McClintock’s method.Keywords: Roller bending, Springback, Analytical study, Empirical modeling, Uncertainty analysis1. IntroductionLarge and medium size tubes and tubular sections are extensively in use in many engineering applications such as the skeleton of oil and gas rigs, the construction of tunnels and commercial and industrial buildings (Hua et al., 1999). The hull of ships may have single, double or higher order curvatures, which can be fabricated sequentially; first by roll forming or bending (to get the single curvature), and then line heating (to get the double or higher order curvature). As roller bending is performed at least once in the sequential process, its efficient performance is a prerequisite for the accurate forming of the double or multiple curvature surfaces (Shin et al., 2001). In view of the crucial importance of the bending process, it is rather surprising to find that roller-bending process in the field has been performed