An Experimental Investigation of Plastic Stress—Strain Relations

Abstract

The paper describes tests carried out on a steel and on an aluminium alloy, with the object of discriminating between and assessing the merits of the “incremental” and “total” plastic strain theories in the region where the elastic and plastic strains are of comparable magnitude. The tests appear to establish that for these two materials the “total” type of theory is incorrect, and in some instances may lead to large errors; for the types of stress applied, the experimental results give strong support to the “incremental” type of theory, and indicate that a particular variant of this theory (which uses the Mises-Hencky function as the criterion of plastic flow) gives results of satisfactory accuracy.