Wedge Design: A Reduced Beam Web (RBW) Connection for Seismic Regions

After the Northridge earthquake, it became clear that welded flange-bolted web connections for deep beams do not have adequate ductility when subject to seismic loading. Previous experimental tests on two such connections for shallow beams based on “wedge design” had achieved adequate strength and ductility. Such beams have a wedge removed from the web and flanges are then reattached. This study aimed to investigate the strength and ductility of “wedge design” connections for deep beams. The finite element method was used to model two pre-tested post-Northridge connections for deep beams of different depths. Wedge design was then applied on these connections, with results showing inadequate connection ductility. A parametric study was therefore carried out to find the best wedge detail. The effects of using different stiffener configurations and double wedge details on the strength, ductility and initial stiffness of connections were also investigated. Finally, the most effective stiffener configuration for the connection is proposed.

[1]  Sheng-Jin Chen,et al.  Ductile Steel Beam-to-Column Connections for Seismic Resistance , 1996 .

[2]  Egor P. Popov,et al.  Design of steel MRF connections before and after 1994 Northridge earthquake , 1998 .

[3]  MarvinB . Cohen,et al.  LESSONS LEARNED FROM THE NORTHRIDGE EARTHQUAKE , 1994 .

[4]  Sean Wilkinson,et al.  A moment resisting connection for earthquake resistant structures , 2006 .

[5]  Cheol-Ho Lee,et al.  Analytical Modeling and Seismic Design of Steel Moment Connections with Welded Straight Haunch , 2001 .

[6]  Chia-Ming Uang,et al.  SEISMIC REHABILITATION DESIGN OF STEEL MOMENT CONNECTION WITH WELDED HAUNCH , 2000 .

[7]  Cheng-Chih Chen,et al.  Behaviour of steel moment connections with a single flange rib , 2003 .

[8]  Adrian Ciutina,et al.  CYCLIC TESTS OF DOUBLE-SIDED BEAM-TO-COLUMN JOINTS , 2001 .

[9]  Cheng-Chih Chen,et al.  Evaluation of reinforced connections between steel beams and box columns , 2004 .

[10]  Ralph M. Richard,et al.  Seismic connection designs for new and existing steel moment frame structures , 1998 .

[11]  Siegfried F. Stiemer,et al.  Improved arc length orthogonality methods for nonlinear finite element analysis , 1987 .

[12]  Archibald N. Sherbourne,et al.  Behavior of eight-bolt large capacity endplate connections , 2000 .

[13]  Cheol-Ho Lee,et al.  Cyclic performance of haunch repaired steel moment connections: experimental testing and analytical modeling , 1998 .

[14]  Stephen A. Mahin,et al.  Lessons from damage to steel buildings during the Northridge earthquake , 1998 .

[15]  Jong-Hyun Jung,et al.  Cyclic seismic testing of steel moment connections reinforced with welded straight haunch , 2003 .

[16]  Chia-Ming Uang,et al.  Cyclic Testing of Steel Moment Connections Rehabilitated with RBS or Welded Haunch , 2000 .

[17]  James M. Ricles,et al.  Ductile details for welded unreinforced moment connections subject to inelastic cyclic loading , 2003 .

[18]  Cheng-Chih Chen,et al.  Cyclic behaviour of unreinforced and rib-reinforced moment connections , 2005 .

[19]  Michael D. Engelhardt,et al.  Reinforcing of steel moment connections with cover plates: benefits and limitations , 1998 .

[20]  E P Popov,et al.  PERFORMANCE OF LARGE SEISMIC STEEL MOMENT CONNECTIONS UNDER CYCLIC LOADS , 1989 .

[21]  James M. Ricles,et al.  Effect of Local Details on Ductility of Welded Moment Connections , 2001 .

[22]  Sheng-Jin Chen,et al.  Enhancement of Ductility of Existing Seismic Steel Moment Connections , 2001 .

[23]  Albert Chen,et al.  Seismic rehabilitation of pre-Northridge steel moment connections: A case study , 2006 .