An Experimental Investigation of the Yielding of Strip between Smooth Dies

Abstract

When two smooth, rigid dies indent a strip of material, the mean pressure on the dies at yield varies with the configuration. In this investigation, die breadth b and material thickness t are varied to cover the range of t/b from 12 to ⅓. This range may be conveniently subdivided into t/b ≥ 1 and t/b ≤ 1, the form of the solution being different above and below the common value 1. The deformation of the strip under the conditions of the test is essentially plane strain, with the exception of two small regions at the edges of the strip. Theoretical solutions for the two ranges have been obtained by Hill (1947) ‡ and Green (1951) respectively, using the equations of Hencky and Geiringer for plane plastic strain. A comparison is made between the experimental values obtained and these theoretical curves which have been derived for an ideal rigid-plastic material.