Steel Frame With Beam-through Joints' Study On The Performance Of Continuous Collapse Under Strong Earthquake

In recent years,the research on the anti-continuous collapse performance of structures has mainly focused on the failure of key supporting members caused by accidental loads such as explosion,impact and fire,which results in the disproportionate continuous collapse of structures.However,for some key components of the structure,there are damage or initial defects,for example,key components are damaged by construction technology.When it is subjected to earthquakes,It will increase the dynamic effect when the structure collapses vertically,As a result,the original damaged parts of the components are damaged first,and destruction continues to develop towards the surrounding components,eventually,a disproportionate continuous collapse occurs.In this paper,the failure of frame columns with original damage caused by earthquake is proposed as a trigger mechanism.The anti-vertical continuous collapse performance of beam-through steel frame structure is studied.The main research conclusions are as follows:(1)According to the existing research on beam through joints and the specifications,considering the requirement of "strong joints and weak members" in earthquake resistance,and the difference of the mechanical properties of the mid-edge joints and the mid-edge joints in the frame,two kinds of T-shaped and cross-shaped beam through joints are designed respectively.(2)Based on the finite element software ANSYS,considering the contact between bolts and beams and columns,the differences between bolts and common column through joints are studied and analyzed,including stiffening ribs,stiffening rib thickness,axillary,axial compression ratio and the grade of bolts.The influence of various factors on the seismic behavior of the joints is obtained by simulating the mechanical behavior of the edge joints and the intermediate joints of steel frames under low cyclic repeated loads.(3)Taking the three-storey spatial steel frame as the research object,the method of dismantling components is adopted.The bottom corner column,side column and middle column are dismantled and the horizontal seismic wave is input.The mechanism of continuous collapse of beam-through joint steel frame with damaged members under earthquake is simulated.