DEVELOPMENT OF A METHODOLOGY TO FORM NET-SHAPE NOSING SHELLS BY THE BACKWARDS TRACING SCHEME OF THE RIGID-PLASTIC FEM

A preform is designed by the backwards tracing scheme of the rigid-pla stic finite element method (FEM) for net-shape shell nosing components without machining after formation. The current process of producing t he shell nosing requires costly machining to produce the final product . Here the backwards tracing scheme of the rigid-plastic FEM, a novel method for preform design of metal forming processes, derives a sound preform for a net-shape shell nosing product. The current process is s imulated by the rigid-plastic finite element analysis to check the met al how involved in the forming with a trial preform and its modified p reform. The two preforms are found to be inadequate for a net-shape sh ell nosing product. The first application of the backwards tracing sch eme derives a preform producing a net-shape product numerically, but i t is difficult to be formed economically. Thus an improved preform is designed by the backwards tracing scheme, which is suitable for net-sh ape manufacturing of the shell nosing components in view of production economy and the forming characteristics of the product. (C) 1997 Else vier Science Ltd.