08-10-2014, 03:58 PM
Seismic design of welded connections in steel moment resisting frames (MRFs) has received considerable attention during the past decade. One of the main reasons identified for the poor performance of beam-column joints during earthquakes was the vulnerability of welds between beam flange and column to premature brittle fracture. The tri-axial state of stress in this region restrains the expected ductile yielding of the weld material there. The major emphasis of past research on this subject has been the improvement of design of beam-to-column connections to achieve superior performance of steel MRFs during strong ground shaking. This research addresses welded strong-axis beam-to-column and column-tofoundation connections. Refined truss models are developed for representing the flow of forces near the joint regions. In beam-column joint region, the inelastic stress distribution is symmetric about the beam neutral axis. For the design of beam-to-column connections, the load flow is represented by an Improved Ktruss model. But, in the column-foundation joint region, the pr