An upper bound analysis of rolling process of non-bonded sandwich sheets

Rolling process of symmetrical non-bonded sandwich sheets was investigated by the method of upper bound. A deformation model was proposed and the mathematical relations of the velocity components were developed. The internal, shear and frictional power terms were derived and used in the upper bound model. Through the analysis, the rolling force, mean contact pressure and final thickness of each layer were determined. The validity of the proposed analytical model was discussed by comparing the theoretical predictions with the experimental data found in the literatures. Effects of various rolling conditions such as the flow stress ratio, initial thickness ratio of the raw sheets and total thickness reduction upon the rolling torque were analyzed. The accuracy of the developed analytical model was very high.