Spatial Free Plastic Forming of Slender Parts—Machine Design, Forming Limits, and Application

Free plastic forming of a slender part means that an initially straight bar, clamped at its both ends, is bent and twisted by an appropriate motion of the end supports only. Emphasis is attached on the computer controlled, precise forming of workpieces with prescribed shape. In this paper the design of an appropriate forming machine at the laboratory scale will be presented. Moreover, the forming limits due to replastification of already completed sections of the part will be illustrated geometrically using one or two “cylinders of admissibility.” Finally, the method will be demonstrated by means of actually formed parts.