Computer aided analysis and design of sheet metal forming processes: Part I – The finite element modeling concepts

The design of a stamping die essentially begins with the geometric development of die-faces using the process specifications in the form of part geometry, material data and stamping criterion such as the thinning limits. Succeeding the completion of the forming interface geometry; the computer aided design models for the punch, the die and the binder tools are generated using the specifications of the manufacturing tools and presses. Nevertheless, an ensuing forming interface geometry is hardly possible right at the first time, and depending on the experience and skills of the methods engineer, several iterations may be required to ensure a die-face design that deforms the blank in to the stamping part at a minimum number operation. It is hence the design for the forming interface that determines a significant part of the tooling design and production costs. The computer aided analysis based on the finite element method may, on the other hand, help the stamping methods engineer to reduce the costly trial-and-error iterations through the qualification of the sheet metal forming process in accordance with the objective stamping criteria. In order to make an utmost benefit of computer analysis in the tooling design for stamping processes, the stamping engineer should have the fundamental understanding of the computational concepts of the finite element analysis in the sheet metal process simulation. The finite elements, the deformation response of sheet metals, and the numerical procedures are key concepts for the stamping simulation engineer in this perspective. The finite element procedures and the element formulations, along with their performance comparisons in an industrial stamping applications are the subjects in this part of the study. The sheet metal deformation modeling and the die-face design concepts are presented in Parts II and III, respectively, together with a set of industrial applications. The practical connotations of the computer aided analysis and design of the sheet metal stamping dies is given and conclusions are drawn.