A Relation Between Maximum Load and Necking in a Tensile Test and a Necking Correction for Flow Stress

摘要

Experiments on soft SAE 1018 steel have shown general agreement with formulae proposed by Beeuwkes stating that incipient necking occurs at a significant strain beyond the maximum load in body-centered cubic metals during a tensile test. The Bridgman necking correction formula (using e - e sub n equal to a/R) applied from incipient necking was not in as good agreement with the experimental data as that of Beeuwkes. The results obtained justify a straight-line extrapolation of the true stresstrue strain curve to represent the corrected flow stressflow strain values from the incipient necking point to fracture when the curve is plotted on a semiarchyperbolic sine graph. (Author)