Performance Study On Steel Bolted Beam-to-Column Connection With Replaceable Fuses

Currently,steel structures are widely used in the construction of commercial and industrial buildings.They provide great strength,constructability and long-life durability.Connections have important roles to provide the structure with enough strength to support the loads and to allow slightly rotation between beams and column.As regards some earthquake events,the huge amount beam-to-column connections have met significant failure that caused very high repair costs.The reduced beam section(RBS)connection is a choice for researchers that can improve the good ductility of steel beam-to-column connections in high seismic zones.However,the repair work is difficult to repair the damaged beam and spends very high repair costs.Therefore,new design ideas are proposed to develop new steel beam-to-column connections that can initially dissipate energy and are easily repaired.This thesis presents the investigation carried out the performance study on the behavior of high strength steel bolted beam-to-column connection with replaceable fuses.The fuses consist of steel cover plates bolted to flange and web of the beam.Low yield point steel(LYP-160)flange and web cover plates are used to improve ductility and energy dissipation capacity.The conventional steel Q345B is used for beam and column.The high strength bolts 10.9 are used to connect beam-to-beam by using cover plates.Seventeen bolted beam-to-column connections with different structural construction details of fuses are established to investigate the performances of this kind of connection.Numerical analyses are performed on detailed three-dimensional finite element models of steel bolted beam-to-column connection with different fuses using ABAQUS software.The load-carrying capacity,monotonic behaviors,failure modes,hysteretic behaviors and energy dissipation capacity are discussed and compared in depth.The behavior of the steel bolted beam-to-column connection with replaceable fuses is significantly affected by the different parameters of fuses.As the increasing of the gap between two beam sections,the local buckling occurs on the flange cover plates.The carrying capacity is increased when capacity ratio,thickness of web cover plates,length of cover plates and distance from column to position of connection are increased.However,it is decreased when distance between bolts and gap between beams are increased.Some specimens reach higher carrying capacity however;dissipated energy of beams of those specimens is also high.The comparisons of load-carrying capacity,hysteretic behavior,failure modes and energy dissipation results are shown that specimen-3,which has capacity ratio ? = 0.70,is the good option connection.The design suggestion of steel bolted beam-to-column connection with replaceable fuses is suggested according to the parameters of fuses.The possible damage is concentrated in fuses(cover plates)and the main structural members of a moment steel frame would not suffer during a strong earthquake.The repair work will be limited only to the replacement of the fuses.