Brittle-Ductile Transition of Bridge Steels. Volume 3. Executive Summary

摘要

An important feature of the mechanical behavior of structural steels is theoccurrence of a brittle-ductile (B-D) transition. The project was carried out to investigate two aspects of the transition. The first was to develop a better understanding of the transition that occurs in bridge steels, and particularly to ascertain whether or not there is a rational for the Barsom-Rolfe temperature shift which is presently used in the AASHTO Guide Specifications. This portion of the project was essentially a literature survey. The second, and larger part of the project, was an experimental program in which crack tip opening displacement (CTOD) specimens of bridge steels and welds were tested well into the transition range. The procedure was limited to temperatures below the 'lowest anticipated service temperature' (LAST). CTOD specimen testing was chosen for the project because these specimens are analyzed by elastic-plastic methods which make it possible to extend the measuring capability above the LAST.