文献类型：会议论文

英文题名：Effects of loading rate, notch geometry and loading mode on the local cleavage fracture stress of a C-Mn steel

作者：Wang, Guozhen[1];Wang, Yuhang

机构：[1]E China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

会议论文集：5th Fracture Mechanics Symposium (FM 2007)

会议日期：OCT 31-NOV 05, 2007

会议地点：Changsha, PEOPLES R CHINA

语种：英文

外文关键词：local cleavage fracture stress; loading rate; notch geometry; loading mode; FEM; steel

摘要：In this work, notched specimens with two notch geometries were tested in two loading modes (four-point bending and three-point bending) at various loading rates at a temperature of -110 degrees C for a C-Mn steel. An elastic-plastic finite element method (FEM) is used to determine the stress distributions ahead of notches. By accurately measuring the distances of the cleavage initiation sites from the notch roots, the local cleavage fracture stress of is measured. The results obtained and combining with previous studies by the authors show that the local cleavage fracture stress of is closely related to the cleavage fracture mechanism (critical events) in steels. The sigma(f) values do not change with loading rate, notch geometry and loading mode, as long as the critical event of cleavage fracture does not change at various testing conditions. The sigma(f) is mainly determined by the steel microstructure, and its scatter is mainly caused by the size distribution of the weakest constituent in steels and the change of the critical events in cleavage process. The sigma(f) can characterize the intrinsic toughness of steels and may be used in a "local approach" model for assessing integrity of flawed structures. The sigma(f) values could be measured by both four-point bending and three-point bending tests.