Selection of materials for avoidance of fracture in welded steel moment frame structures subject to seismic loading

A short description is given of the results of finite element analyses of welded steel moment resisting frames in work at UMIST to determine relationships between applied crack tip severity and crack size under seismic loading conditions representing those experienced in the Northridge earthquake for different forms of strengthening of the beam to column connection. A summary is given of the IIW Recommendations for Assessment of the Risk of Fracture in Seismically Affected Moment Connections showing how these are consistent with the results of the research. A brief discussion is given of differences in other approaches to avoidance of fracture in moment resisting frames.