On the guillotining of materials

An analysis is presented for the mechanics of guillotining and experiments on a number of solids are described which agree with the theory. Irreversible work not associated with the cutting process (i.e. work of bending or plastic flow) is least when guillotining thin flexible sheets, and experiments on such materials permit determination of the specific work of fracture, once frictional effects have been compensated for. The results are compared with values of fracture toughness obtained by other methods. The analysis is extended to cover the formation of burrs at the cut edge of metal sheets. Comments are also made about the type of friction in guillotining and other scissor-type devices having “set” blades which scrape along one another during cutting.