Reserve Capacity of Beam-Column-Gusset Connections in Concentrically Braced Frames
Regions of low and moderate seismicity typically employ a seismic response modification factor of R = 3 for concentrically braced frames (CBF). Since the R = 3 seismic design approach has little to no scientific development, research is being conducted to determine whether this value is acceptable. Also, alternative approaches that are rational and reliable are being researched. An important requirement for evaluating the R = 3 design approach and for developing new design approaches is to study the reserve capacity provided by beam-column-gusset connections in CBFs. This research evaluated the seismic performance of beam-column-gusset connections in CBF’s. Large-scale cyclic load tests were performed on three distinct beam-column-gusset connection configurations. Variations in connection type (double angle or end plate), weld type, and bolt location were explored. Differences in rotational stiffness, strength, and ductility were compared and presented. Based on the results, further recommendations for beam-column-gusset connections may be provided.