Development of a Computer-Aided Analysis Method for Sheet Material Forming Processes

The computer-aided engineering method can be incorporated in a number of material processing operations to reduce engineering, manufacturing and material costs. With this objective in mind, an interactive computer software package has recently been developed to predict the degree of success or failure of formed sheet metal parts at the design stage to minimize the traditional trial and error process. For example, given the material properties, the rate of deformation, the geometry, and loading boundary conditions, the program computes the distribution of major and minor strains in the part to be formed. Concurrently, the limiting strain forming limit diagrams corresponding to the particular material are computed based on the defect growth model. The computed strain distribution is then directly compared with the forming limit diagrams so that any design and processing changes can be made at the computer terminal. Several examples of computed results are presented which, in turn, are directly compared with the measured strain distributions obtained from the circular grid technique. Included in the experimental work are aluminum-killed steel, enameling iron, and high strength steel sheets.