MODELING HOT FLAT-ROLLING OF COMPONENTS HAVING CURVED PROFILES .1. DEFORMATION ANALYSIS

A complete mathematical model of the Variable Gap flat-Rolling (VGR) p rocess for producing components with variable thickness under hot work ing conditions is presented. The model is composed of separate submode ls for deformation, flow stress, roll force and temperature. Sub-model ling approach allows changes and new developments to be easily incorpo rated. A three-dimensional deformation analysis of the workpiece based on the upper bound theorem is carried out. A simple velocity field is proposed. To preserve the theoretical consistency, an equivalent coef ficient of friction is adopted for roll force calculation. Furthermore , the basic assumption of rigid perfectly-plastic material is modified by introducing the concept of isotropic rate-dependency. Satisfactory results were obtained in spread, torque and force prediction.