Experimental Study On Seismic Behavior Of Replaceable Steel Beams With Buckling-restrained Cover

A replaceable steel beam with buckling-restrained cover plate was proposed and cyclic loading test of 9 replaceable steel beams and 2 replaceable steel beams with RC slab was carried out on to study the influence of strength ratio coefficient,details of buckling-restrained cover plate and the use of RC slab on seismic and resilient performance of the replaceable steel beams.Based on the analysis of test results,main obtained conclusions are as follows:(1)The proposal replaceable steel beam can realize that the plastic deformation of all specimens is concentrated on the replaceable connecting plate while other irreplaceable parts remained in the elastic domain as intended.(2)Connecting plate could be replaced with relatively ease and short time after finishing each loading protocol.The overall performance of each pair with the same parameters are almost identical.The hysteretic curves are in good agreement,also the bearing capacity,stiffness and energy-dissipation capacity are equivalent.(3)Strength ratio is the key factor to affect strength-matching relationship of replaceable and irreplaceable part and the final failure mechanism.When the strength ratio is less than 0.8,all the damage is concentrated on the connecting plate;when the strength ratio is more than 0.8,that will be transferred to the irreplaceable beam section.The closer the strength ratio is to 0.8,the higher the utilization ratio of steel beams is,and the more economical the design of steel beams is.(4)The buckling of the connection plates of the beam flanges covered with buckling-restrained cover plates is not as obvious as that without the cover plates.Strength of such specimens showed no degradation up to 0.4 chord rotation.(5)The detail of local opening in the RC slab attached to the top flange of the steel beam had little influence on the combination of RC slabs and steel beams.Compared with steel beam,the bearing capacity,stiffness and energy dissipation capacity of steel beam with RC slab are obviously improved.The specimens can also achieve damage concentration,rapid replacement and earthquake-resilient.