PLANE-STRESS, PLANE-STRAIN, AND PURE SHEAR AT LARGE FINITE STRAIN

P. W. Bridgman's rejection of the Prandtl-Reuss classical plasticity theory for finite strain in steel is reassessed. His conclusion in 1946 was based on data from his two-dimensional compression experiment. In terms of a modern incremental theory of finite strain plasticity in which stress and strain tensors are redefined, Bridgman's experiment provides a state of pure shear. In these new terms, the Bridgman experiment becomes but one of many two-dimensional situations in plane stress or plane strain amenable to analysis. The present experiments include measured finite strain of over 40% and measured decreases in volume. For the appropriate strain tensor, the finite strain and rotation are shown to be describable by a relatively simple kinematics.