METHOD FOR PREDICTING STRESSES THAT PRECEDE THE FORMATION OF MACROCRACKS OF VARIOUS LENGTH IN SHEET MATERIAL BY TESTING THE SMALL-SIZE SAMPLES OF THE MATERIAL

摘要

The proposed method for predicting stresses that precede the formation of macrocracks of various length in sheet material by testing the small-size samples of the material consists in exposing the sample to static load, providing the uniform deformation of the sample under the load, measuring the length of the sample and the load acting on the sample at the instant that corresponds to the start of the macrocrack formation, determining the variation of the load when the sample elongates due to the macrocrack evolution, and plotting the characteristic that determines the relative length of the macrocrack as a function of stresses in the sample. The present invention provides a possibility to predict stresses that precede the formation of macrocracks in sheet materials irrespective of the length of the material.