The Angle of Fold and the Plastic Work Done in the Folding of Developable Flat Sheets of Metal

Under the condition of inextensibility, an initially flat sheet of metal can be folded along straight lines or a curved line to produce various surfaces. The angle of fold and the plastic work done in folding along a line are examined for a series of cases, such as folding-up into a prism and a frustum, folding on a cylinder along a circular arc, and more generally, folding on a developed surface along an arbitrary curved line. Some numerical results are given.