Abstract
A procedure for detemtining the siress-strain curve including post-necking strain is proposed. Hourglass type specimens were used for tensile tests, and the stress-strain curves were identified through an iteration process using fmite element analysis. The strain at the position of minimum diameter was measured by digital image correlation. This procedure was applied to carbon steel and the radius of the minimum section of the hourglass type specimen was changed. The procedure could derive the stress-strain curve including the post-necking strain. It was revealed that the true stress-strain curve could be approximated well by the power law equation and the curve could be estimated by using the stress-strain relation for before-necking strain.
