Test Research And Finite Element Analysis On Hysteretic Behavior Of A Brace Dissipated Energy By Yielded Perforated Web

Under the rare earthquake,the braces of the central braced frame structure are subjected to compression buckling under repeated loads,resulting in the decrease of the overall stiffness and bearing capacity of the structure.In order to ensure that the main structure of the frame will not be damaged under the earthquake,so that the support can not buckle and fully dissipate energy.In this paper,a brace dissipated energy by yielded perforated web is proposed.The slotted damper is introduced into the traditional support,and the end of the support is cross-section of cross duplex steel cross-section,in which the I-steel web of the energy dissipation part has a long circular hole,dissipated energy through the plastic deformation of the stripes between holes in the perforated web.In this paper,the hysteretic behavior of energy dissipation brace with perforated web and energy dissipation braced frame structure are studied by means of experiments and finite element analysis:(1)Three specimens of BDW were designed and fabricated.The low cycle cyclic loading tests were carried out to analyze the axial bearing capacity,stiffness,strength,hysteretic energy consumption and failure characteristics of BDW.The test results show that the energy dissipation of the brace mainly depends on the yielding and plastic dissipation of the stripes between holes in the I-beam web at both ends of the brace that effectively avoid the damage of energy dissipation brace.In the process of loading,the stripes between holes firstly enter into plasticity to consume energy.With the increase of the load,the cracks appear at the semi-circular holes section of the stripes between the holes and gradually expand to tear,and finally the stripes between the holes break.The intermediate I-beam is always elastic.When the total number and parameters of holes are the same,the specimens with double-layer perforated web have better deformation capacity and slightly higher bearing capacity than those with single-layer perforated web,and the flange plate steel can be saved.(2)The ABAQUS finite element analysis software is used to simulate the test specimen.The comparison between the test results and the finite element simulation results verifies the rationality of the finite element simulation.Combined with the test phenomenon and the stress distribution of the finite element analysis,the failure criterion of the energy dissipation support is defined.At the same time,four series of 17 full-scale braces dissipated energy by yielded perforated web are designed,and the finite element analysis is carried out.The influences of the hysteretic performance of energy dissipation braces on the length and width of the stripes between the holes,the thickness of the web and the layers number of the perforated web are analyzed.The results show that the larger the length,width and thickness of the slab between the holes,the larger the bearing capacity and initial stiffness of the brace dissipated energy by yielded perforated web.The hysteretic behavior of energy dissipation braces with single or multi-layer perforated webs are similar,but when three-layer perforated web are used,the out of plane deformation of the web with holes is larger.Considering the bearing capacity and deformation capacity of the energy dissipation brace,it is suggested that h/b ranges from 4.3 to 5.(3)The hysteretic performance of energy dissipation braced frame structure with different parameters,which is composed of welded connection or plate hinge connection,is analyzed by using ABAQUS finite element analysis software.The results show that the dissipation energy of braced frame increases with the increase of energy brace.In the early stage of loading,the energy consumption of braced frame is mainly dissipated by energy dissipation brace.With the increase of the story drift angle,the energy dissipation ratio of the brace gradually decreases when beam and column enter plasticity.Both the plasticity of the plates of brace and the flange of the column foot increase.The effect of hysteretic performance of the brace and braced frame are similar by the welded connection or the platehinge connection at the end of the brace.The bearing capacity of the frame under plate-hinge connection mode is slightly higher.