A universal equation governing engineering stress-strain curves of polycrystals

Abstract

A universal equation for understanding various phenomena observed on the engineering stress-strain curves of polycrystals, which includes the Hall-Petch relation concepts, is derived. The derivation of the equation begins from the simple condition that the given constant strain rate is the sum of the elastic strain rate and the plastic strain rate. The physical meanings for the various phenomena on engineering stress-strain curves are analyzed from the viewpoint of the competition between two strain rates.