FEM dynamic simulation and analysis of the roll-bending process for forming a conical tube

Abstract

Abstract A general simulation model is developed to study the dynamic process of roll plate bending using finite element method (FEM). In this work, the continuous three-roll pyramidal bending configuration with conical rolls is used to bend a thick plate into a conical tabular shape. We present the kinematic relationship existing between rolls and workpieces, the geometrical setup and the finite element model. The dynamic forming process, going from the initial plate to the finished conical shape, as well as the stress variation of the workpiece over time, can be visualized during the course of the simulation. This 3D simulation is based on the elastic–plastic explicit dynamic finite element method under the ANSYS/LS-DYNA environment. A numerical algorithm is also developed to quantify the dimensional and geometrical accuracy of the produced conical shape with respect to the desired truncated cone. The Levenberg–Marquardt nonlinear algorithm is implemented in this step in fitting the point clouds generated by the FE software into a least-square cone, which is used for comparison with an ideal one. Parametric studies are carried out to investigate the effects of various parameters, including friction coefficient, on the quality of the final shape, based on simulation results. The required forces and torques in terms of plate thickness and roll configurations are illustrated. This work is conducted in an attempt to study the feasibility of using the roll-bending process with thick plates and to provide engineers with a convenient numerical tool for optimizing process parameters.