Study of large plastic strains and fracture in metal elements by photoelastic coating method

The photoelastic coating method has been developed to investigate large strains in metals with the help of the coatings made from sensitive optical materials. The strain changes have been within the range from −50% to 220%. Some fracture mechanics problems considering large strains were solved: first, the stress-strain condition was determined at the localized necking of a thin steel bar; second, the stress field near the sharp notch's tip in an aluminum bar was obtained; also, the kinetics of plastic strain development was studied. Plane problems of strain determination at the macrolevel were investigated. The investigations were sponsored by the Russian Fund of Fundamental Investigations (Project No. 02-01-00222).