Large-Scale Axial Fracture Experiments of High-Toughness Steel

Abstract

Fracture resistance of modern bridge steels has improved through advances in material production techniques. The enhanced performance has been quantified through a number of material characterization studies and large-scale experimental research programs. Results from earlier studies conducted beginning in the late 1990s demonstrated the extreme potential of high-toughness materials for use in bridge applications. More recent studies have focused on identifying the toughness level required to potentially eliminate the concern of sudden brittle fracture in the presence of a small flaw in new structures fabricated with such materials. The research consisted of material characterization, full-scale fracture testing, three-dimensional finite-element analysis (FEA), and an analytical parametric study. From the work, the idea of an integrated fracture control plan (FCP) resulted. In an integrated FCP, the likelihood of brittle fracture is minimized through a series of interrelated components which interact in a rational and quantifiable manner. The current paper explores the results from large-scale experiments on axially loaded plates with reference to a separate material characterization study and large-scale flexure experimental results. Results of the study demonstrated fracture toughness demands calculated using FEA compared favorably with 1T single-edge bend [SE(B)] material characterization experiments and large-scale flexure experiments.