Nonproportional cyclic deformation: Critical experiments and analytical modeling

Different deformation response due to nonproportional loading has been the subject of numerous experimental and analytical investigations. Critical experiments and methods of comparison to quantify nonproportional hardening are presented. In view of the existing parameters for describing the nonproportional hardening, the concept proposed by Tanaka appears to be the most robust. This article will concentrate on a modified Tanaka model and its performance in view of the experimental observations on two different materials, a 304 stainless steel and a 1045 steel. Further modifications are discussed that will improve the modeling of the experimentally observed nonproportional hardening phenomena. (C) 1997 Elsevier Science Ltd. All rights reserved.