Grishchenko V. Interrelation between local and nominal characteristics of fracture of structural steel with bcc lattice under conditions of stress concentration.

Thesis is dedicated to research laws of the process of initiating brittle fracture in a highly non-uniform force fields created by stress concentrators. And for finding, on this basis, interrelation between local and nominal characteristics of brittle fracture of structural steel with bcc lattice. In this paper the results of experimental studies and computer modeling uncovered patterns of change in the value of local characteristics initiation of brittle fracture in a wide temperature range T = -196 ... + 20 It was proposed microscopic model of brittle fracture initiation in a neighborhood stress concentrators. It was established that the key effect which controls the ability of structural materials resist to brittle fracture under conditions of stress concentration is exceeding the value of the local stress fracture above the brittle strength of a standard sample under uniaxial stretch. Оffered experimentally determine the degree of embrittlement of structural steels in conditions of stress concentration and assessment of their qualities as construction material.