Sheet Metal Bending Processes & Die Design

Bending is a process by which a straight and flat sheet metal is transformed into a curved surface through the use of standard die sets. The sheet metal operations carried on press are grouped into two categories, cutting operations and forming operations. In cutting operations, the workpiece is stressed beyond its ultimate strength. The stresses induced in the metal by applied forces are shearing stresses. In forming operations, the stresses are below the ultimate strength of the metal. The forming operations include bending, drawing, redrawing, squeezing. The inner sheet radius at the end of bending is classified as one of most significant parameter in V-die bending. This radius determines the strain level in the bending region and thereby whether there is risk of fracture in sheet metal at the bend line can be minimized, if the processor knows the minimum bend radius for the particular material. In this book, different types of bending method are analyzed. The theoretical analysis is developed for minimum bend radius considering the failure criterion.