The Research On The Mechanical Behavior Of Tubular Column To I-steel Beam Connections

With the rapid development of national economy，steel structures have been appliedwildly in our country. Because of the benefits of tubular column such as making use ofmaterial sufficiently，light weight of structure，low request of base and so on, the applicationof square tubular column to I-beam connections is more and more popular. Because weldingdiaphragm in traditional box-column connection was complicated to affricate and expensivewith even bad quality，so it is of great significance and engineering benefits to research onbehaviors of external T-stiffener square tubular column to I-beam connections.Using the software ABAQUS finite element analysis, elastic-plastic analysis on externalT-stiffener square tubular column to I-beam connections under vertical loading was conducted.Considering the change of column thickness, stiffener size, mechanical behavior of tubularcolumn to I-steel Beam Connections was systematically studyed in this paper. Results showedthat: under monotonic loading, stiffener web and flange connection first appeared high stressarea in elastic stage; in elastic-plastic stage, beam flange and stiffening rib connection endappeared having a region through the flange of beam web and plastic, the correspondingposition of web came into the plastic; gradually expanded to the center, the maximum stressof regional metastases transferred to the center of beam flange and stiffening rib connectionend. finally, the beam flange stiffener connection ends formed plastic hinge. Due to thestrengthening rib, node deformation in destruction was not large. But the beam, the lowerflange and stiffening rib connection end deformed a lot. Under cyclic loading, the connectionshad full hysteretic curve, energy consuming was ideal. The stress concentration phenomenonat the corner flange and stiffening rib and column connection could easily show, so inpractical engineering corresponding measures should be taken to avoid stress concentration. Ttype stiffener took a part of stress; beam flange width and stiffening rib section height occupied the full width of column flange; connections stress distributed uniformly, all ofwhich improved the stress performance of connections. The length of stiffener weresignificant in influencing the bearing capacity and ductility performance, which increased thelength of stiffener benefiting the passing of the moment of beam end to the column webstiffener, at the same time, stiffener flange connected with the column of the stressconcentration phenomenon were more and more serious. Reasonable length of stiffenershould be chosen to improve connections stress performance, and it were not significant forcolumn wall thickness on the bearing capacity and ductility. The increase of column wallthickness could not be solely relyed on to improve the stress performance of node, instead,some economical column thickness should be considered.