Forces and coefficient of friction during cylindrical three roller bending

Abstract

Three roller bending process is one of the processes of forming cylindrical shells, for manufacturing drums, pressure vessels, windmill towers, etc. During the bending process, forces on the rollers must not exceed their bending capacity. Along with operational and material parameters, the forces exerted during bending and power consumption are affected by the coefficient of friction at the roller-plate interface. It is difficult to determine the coefficient of friction practically during three roller bending process. An attempt is made to determine the forces and friction coefficient at each roller–plate interface, through derived mathematical model, using experimental results. The variation of coefficient of friction under the higher loading conditions was also determined as a case study. With the present mathematical formulation along with the coefficient of friction, the forces at each roller–plate interface could be determined more precisely. The determination of forces and friction coefficient helps in deciding operational and design parameters of the bending machine, respectively.