Study On The Ductile Joint Of Steel Fream' Lateral Stiffness And Strengthened Measures

With the development of structure design theory and material performance, the steel structure tends to be more light and thinner . The importance of the steel-frame stability count is prominent than ever before . After the big earthquake in Northridge America and Hanshin in Japan ,the dog-bone rigid joints has been used into the steel-frame . But the local weaken of the steel beam flange must cut down the anti-lateral capability of the steel beam while the structure 's level deformation capability is a very vital criterion to measure the overall stability of the structure. Therefore , it is necessary to make a study on the anti-lateral capability of the steel-frame 's dog-bone rigid joints.This paper is about steel frame with dog-bone moment connection and takes structural story drift as control index . It studies on the anti-side ability of steel frame by means ETABS . Main results are as follows:1,This paper proved that through example analysis : the anti-side ability of Steel frame was decreased due to partial weaken of steel beam flange on steel frame with dog-bone rigid joints.2,The establishment of four different high bottom of the steel frame model for response spectrum analysis shows that height of the bottom layer on buildings has different effect on drift of story, story drift angle of displacement .The most influential effect is on drift of story. With the increasing height of bottom layer ,the growing speed of story drift is more and more fast. The most influential effect is on the first floor for the story drift, he story drift angle. But the effect on story drift is more obvious than one on story drift angle.3,Using the same arrangement form support in one span to calculate respectively the top node displacement,story drift and story drift angle of the sixth layer and the fifteenth layer of the frame. The results showes that: the ratio of the maximum displacement value and the minimum displacement value and the ratio of the maximum fleet angle value and the minimum fleet anglevalue of the high-rise structure are less than those of multilayer structure. It shows that: with the increasing height of building, the restriction effect of vertical support to top node displacement of the structure becomes more and more unclear.4,As to the location of arranged supporting, the calculation data from multi-story and high-rise building draws the same conclusion during the quantities of arranged support of intermediate span and nearby side span are the same and the steel consumptions on supporting component are the same .When the support arrangement put particular emphasis on the middle span, the anti-side ability of steel frame is the best , the story drift and story drift angle of various floors are minimum . When the support arrangement is nearby the intermediate span ,the anti-side ability of steel frame is more better .Compared the situation that the support arrangement is at the side-span and the situation that the support arrangement is at 1,3,4,6 span, anti-side ability of the steel frame on the two situation is close ,but worse than the first two schemes.5,The vertical support changed staggered layout can improve structural deformation form, reduce structural apex side-movement and caused story drift of various floors to tend to consistently. The distributed arrangement of vertical braced is the important way to decreased structural displacement.