CONSTRUCTION OF CURVED LIMIT DEFORMATIONS OF MATERIALS

The analysis of construction curves limiting deformations metals is carried out in the work. It established that traditional test methods, such as deposition and stretching cylindrical specimens, do not ensure constancy stress state, therefore contribute to history deformation curves. During deposition, there an increase state due curvature lateral surface sample (barrel formation), which caused by friction at ends. And when stretched, index also increases, a result formation neck loss resistance deformation. Therefore, measures were considered reliable results boundary deformations, excluding influence When settling, include use plastic, softer than material, foil ends samples gradual removal edges hole their grinding or without foil. In addition, experimental-calculation method was considered, involves ways correction limit using criterion deformability. stretching, case formation, linearly depends on ratio radius its diameter. equation can take into account ultimate given. To experimentally determine tensile deformation, rolling specimens wedge with rolls whose radii during proposed, eliminates appearance neck. Boundary strain be constructed sufficient accuracy for torsion values are obtained approximated dependences tested different metals.