Vliv tloušťky zkušebního tělesa a teploty na lomovou houževnatost konstrukčních ocelí

Abstract

This diploma thesis deals with a study of an effect of test specimen thickness and temperature on fracture toughness A 508 steel. The theoretic part occupies by fracture toughness, factors that influence it and methods of its assessment. There are also two areas of fracture mechanics (namely linear elastic fracture machanics and elastic-plastic fracture mechanics) defined in light of resistence of the cold-short fracture. In the experimental part of this work, there is, at first, the effect of temperature on fracture toughness of the test bodies thickness 25mm studied. It has been proved that the fracture toughness declines together with the decreasing temperature. In the second part, there has been the effect of test specimen thickness on fracture toughness studied (the eperiment was realized on test bodies of thickness 15mm and 25mm. It has been proved, that the thickness influences fracture toughness, which declines the more the thicker the test body.