Study On Seismic Performance Of Y-Eccentrically Braced Frames With Replaceable Links

Y-eccentrically braced frame,of which links firstly enter elastoplastic condition to dissipate energy under earthquake effect and non-energy dissipation elements(beams,columns and so on)develop plasticity when the deformation is too large,is a type of ideal damage-control structures with significant yielding sequence.Links,which are vertically connected to beams in Y-eccentrically braced frames,mainly produce shear deformation in horizontal direction and have little influence on beams and slab.As long as links use replaceable connections,it can be realized that the structure function of Y-eccentrically braced frames recover quickly after earthquake.For the moment,there are few studies on Yeccentrically braced frames with replaceable links and the range of rapid recovery of structural function at home and abroad.Finite element analysis software ABAQUS was used to simulate Y-shaped eccentrically braced frames with high-strength bolted end-plate connected links.The reasonable range of story drift ratio for rapidly recovering structure function was presented in this article.The main researches are summarized as follows:(1)Refer to the relevant specification and literature,adopt ETABS to design a 3×5-span 12-story Y-eccentrically braced frames with replaceable links and select a one-span 3-story structure as the BASE specimen for solid finite element analysis.(2)Establish a finite element model of the BASE specimen by ABAQUS,analyze the existing related tests and verify the modeling approaches.(3)Analyze the seismic performance of the BASE specimen through push-over curves,hysteretic curves,skeleton curves,stiffness degradation curves,ductility and energy dissipation.Comparing with the HJ specimen whose links adopt welded connection,results show that appropriately designed high-strength bolted end-plate connection has enough strength and stiffness and the BASE specimen has the same seismic performance as the HJ specimen.(4)According to the feature of damage-control structures,the method to determine the reasonable range for rapidly recovering structure function of Y-eccentrically braced frames is presented,verified by the BASE specimen,two series of specimens with different highspan ratios of structure and one series of high-strength steel specimens.Considering the influence of high-span ratio and strength grade of steel structure,the reasonable range for rapidly recovering structure function by replacing links is given.