Study On The Performanceof The Outer Reinforcement Ring CFRT Column-beam Node Under Monotonous And Low Cycle Cyclic Loading

In recent years,the rapid development of concrete filled steel tube structure in China,but most of the domestic steel tube concrete beam-column joints is still mainly in the form of traditional.Outer reinforcement ring CFRT column-beam node relatively ordinary reinforced concrete beam-column joints has considerable advantages.Although the outer reinforcement ring CFRT column-beam node cost performance ratio is high,but its under the seismic action,is still the varying degree damage happens.This article uses the ANSYS three-dimensional simulation,reasonable selection of unit type,material properties and reasonable meshing,get accurate stress distribution node area as a result,it can intuitively reflect the stress of the node details;In addition also,in this paper external outer reinforcement ring CFRT column-beam node has carried on the depth analysis.In this paper,carrying out the work mainly include:(1)In accordance with the requirements of the technical specification for concrete filled steel tube structure,set up 19 finite element model of outer reinforcement ring CFRT column-beam node and the finite element software ANSYS to different detail size of the node model simulation analysis of monotonic loading.(2)Using ANSYS on the beam transverse stiffener different spacing of the node finite element model to do the simulation analysis of monotonic loading,and summarizes the factors each other finite element modeling of CFRT column-beam bearing capacity and stiffness influence degree.(3)Of four kinds of new types finite element model of outer reinforcement ring CFRT column-beam node separately carried on the analysis,the monotonic loading and cyclic loading is investigated under the two load finite element model of the mechanical properties.(4)Through results ANSYS calculated,further check the node under the ultimate load beam and strengthening the weld strength.In this article,through calculation the conclusion mainly include:(1)The results ANSYS calculated of each node under monotonic loading have good agreement with the results of theoretical calculation,it infers the outer reinforcement ring CFRT column-beam node finite element simulation analysis of a node is reliable,the node finite element model on the beam end displacement reaches about 4 mm is not just complete combine,displays the semi-rigid nodes;In the nodes of various sizes,high beam,flange thickness,web plate thickness effect on stiffness and bearing capacity,the steel tube wall thickness,rigidity and bearing capacity ofaxial compression ratio on the node finite element model had little impact.(2)With the finite element model of beam node transverse stiffener stiffness is better than no transverse stiffener beam,but the effects of stiffening rib on bearing capacity of node is not better.(3)The root of the beam flange thickness finite element modeling of large seismic capacity is much higher than other forms of node;Node failure,the formation of the place where the plastic hinge in the beam-column joints outside,meet the needs of "strong column weak beam" seismic design requirements.(4)On the beam end reaches limit load,beam total cross-section failure happens,calculating the welds conform to the requirements of the specification,the node finite element model can reflect the good ductility,total cross-section before destruction,weld damage will not occur.