process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set

摘要

For effective manufacturing of a doubly curved sheet metal,a novel sheet metal forming process is proposed.The suggested process uses a Line Array Roll Set(LARS)composed of a pair of upper and lower roll assemblies in a symmetric manner.The process offers flexibility as compared with the conventional manufacturing processes,because it does not require any complex-shaped die and loss of material by blank-holding is minimized.LARS allows flexibility of the incremental forming process and adopts the principle of bending deformation,resulting in a slight deformation in thickness.Rolls composed of line array roll sets are divided into a driving roll row and two idle roll rows.The arrayed rolls in the central lines of the upper and lower roll assemblies are motor-driven so that they deform and transfer the sheet metal using friction between the rolls and the sheet metal.The remaining rolls are idle rolls,generating bending deformation with driving rolls.Furthermore,all the rolls are movable in any direction so that they are adaptable to any size or shape of the desired three-dimensional configuration.In the process,the sheet is deformed incrementally as deformation proceeds simultaneously in rolling and transverse directions step by step.Consequently,it can be applied to the fabrication of doubly curved ship hull plates by undergoing several passes,ha this work,FEM simulations are carried out for verification of the proposed incremental forming system using the chosen design parameters.Based on the results of the simulation,the relationship between the roll set configuration and the curvature of a sheet metal is determined.The process information such as the forming loads and torques acting on every roll is analyzed as important data for the design and development of the manufacturing system.