Fracture Strength of Welded Flange-Bolted Web Connections

Abstract

In 1994, California's steel building frames withstood the 6.8 magnitude Northridge earthquake without collapse or casualties. Severe damage, however, was sustained by the welded flange-bolted web connections: at the column-weld interface brittle fractures were discovered. Using linear elastic fracture mechanics this unexpected failure mechanism is explored in this work. Post-Northridge connection test results and recent finite-element studies supply the springboard for this investigation of the fracture strength of welded flange-bolted web connections. A method of predicting the brittle fracture strength of these connections is presented and validated. The probability of brittle fracture is also investigated.