Analytical investigation of unbounded clad sheets by utilizing slab method and employing hybrid friction through asymmetrical rolling

In this paper, according to slab method an analytical model is presented to study asymmetrical rolling process of unbounded clad sheets; in which, based on the process conditions, both of the two frictional models, including constant shear frictional model and coulomb frictional model, are applied. In the proposed model, vertical sides of the slabs include non-uniform normal stresses and shear stresses distribution. Equilibrium and yield equations for each portion of upper and lower sheets in the quaternary zones of deformation region are extracted by considering assumptions such as, large contact angle and utilization of new stress field, which is tried to be as near as possible to the real situation. Then, the bonding point position of the sheets, as well as, the upper and lower neutral points’ position, are determined. Moreover, the trend of the most important process quantities such as, pressure, force and torque of the process which are influenced by the sheet thickness reduction, ratio of speeds and work rolls radii, are investigated. Additionally, the proposed model is studied via finite element process simulation using ABAQUS software. Eventually, the results of the proposed model is compared with the analytical and experimental results of other researchers.