Analytical approach to the cold-and-hot bond rolling of sandwich sheet with outer hard and inner soft layers

This study derives the stress field of the cold-and-hot bond rolling of unbounded sandwich sheet with outer hard and inner soft layers at the roll gap by using the direct formulation without a Runge Kutta numerical method. Constant shear friction between the roll and the sandwich, and constant shear friction at the interface of the unbounded region are assumed. Due to the sandwich sheet being unbounded before rolling, three-layer sheets are not bonded at the entrance of the roll gap. Therefore the stress field of the roll gap for this study is different from that for the sandwich sheet bonded firmly before rolling. The neutral point between the roll and the sandwich sheet, the rolling pressure distribution along contact interface between the roll and the sandwich sheet, the horizontal stress of whole sandwich sheet, the horizontal stresses in the component layers of sandwich, the shear stress at the interface of sandwich sheet, the rolling force, and rolling torque, etc. are easily and effectively calculated via this model. Furthermore, it is of great important to obtain the bonding point at the interface and the thickness ratio of sandwich sheet at the exit from this study. Additionally, the bonding conditions of the unbounded sandwich sheet are found to avoid the failure in bond rolling. This study proposed is suitable for the on-line bond rolling; it offers useful knowledge to conduct the experimental bonding conditions.