EFFECTS OF MATERIAL TOUGHNESS AND PLATE THICKNESS ON BRITTLE FRACTURE OF STEEL MEMBERS : Research on steel fracture Part 1

Abstract

An extensive research project has been devoted to finding out the causes and their physical relationships on brittle fracture of steel structures which were observed in the disaster of the 1995 Hyogoken-Nanbu Earthquake. This paper shows the results of one of the research subjects, in which full-scale fracture test was carried out to clarify the effects of material toughness and plate thickness on the plastic deformation capacity prior to brittle fracture. Major findings are as follows : material toughness in terms of Charpy impact energy gives a substantial effect on the plastic deformability, while plate thickness is of less importance ; statistical estimation shows the deformability of 95%-confidence level is scarcely dependent on assumed probability functions ; and numerical simulation for load-deformation curves of steel members indicates strain concentration and axial force in tension are significant for the deformability governed by brittle fracture.