Stress Concentration Analysis Of Blind Bolt Connection Of Square Steel Tube Column-H Steel Beam

With the gradual development of the nodes in the fabricated steel structure housing,the high-strength bolt connection has gradually become an important connection method for the assembled steel structure beam-column connection node.The one-way high-strength bolt is a new type of high-strength bolt,and under certain circumstances,the one-way bolt can achieve the same mechanical properties as ordinary high-strength bolts,and has wide application prospects in fabricated steel structure houses.For this new type of high-strength bolt,many scholars at home and abroad have carried out different degrees of research on their static and seismic properties,but little research on their fatigue properties,and stress concentration is a key factor in the occurrence of fatigue damage.Mutations in the form of sections or defects in components can cause stress concentration.The existence of threads in bolts is a congenital defect.For bolts,stress concentration is inevitable.Therefore,it is of great significance to study the stress concentration of bolts.The specific content of this study and the conclusions of the work are as follows:1.Through a large number of domestic and foreign related literatures,the papers on the tensile,shear and seismic resistance of unidirectional bolts are summarized and classified.The ultimate tensile capacity and ultimate shear capacity of unidirectional bolts with different fastening forms are listed.Calculate the formula.Aiming at the mechanical properties of the beam-column joints connected by one-way bolts,the calculation formulas of the stiffness and ultimate bending capacity of the joints are summarized through the query of related literatures at home and abroad.2.Create a single unidirectional bolt model by using ABAQUS finite element simulation software,from unidirectional bolt thread elevation,thread form,model mesh division form and local encryption form,adjacent thread influence,bolt diameter,screw length,thread The length,the radius of the bottom of the thread,and the size of the tapered nut are analyzed in ten aspects of the stress concentration of the one-way bolt,and the stress concentration factor affected by the thread form is sorted from small to large,and three models are studied from the modeling results.The influence of parameters on the stress concentration factor is established,and the mathematical expression formula of the stress concentration factor K_t of the one-way bolt is established.3.Using the ABAQUS finite element simulation software to establish a one-way bolt-level end plate connection beam-column joint model,and coMPare and analyze with the previous experimental research,and then from the thickness of the connecting end plate,the wall thickness of the square steel pipe,one-way The bolt stiffness and the strength of the square steel tubular column are used to study the overall stiffness of the joint and the flexural capacity of the joint.The load-displacement curve of the ABAQUS software results the bending moment-turn curve of the joint and analyzes four different parameters.IMPact on node performance.