Numerical Simulation Analysis Of The Mechanical Performance Of The Beam-column Concealed Corbel Angle Steel Connection Joints Of The Fabricated Frame

Fabricated structure is a structural form that the country has developed vigorously in recent years,and it is the only way to take the road of sustainable development of the construction industry.Compared with the traditional cast-in-place structure,the fabricated structure has the advantages of high production efficiency,low environmental pollution,short construction period,stable quality,and low labor intensity,but its integrity and seismic performance are not good.For fabricated concrete frame structures,the beam-column joints play a decisive role in the seismic performance of the structure,and the fabricated frame beam-column concealed corbel angle steel connection joint is a new type of joint connection,and it is found through experiments that it has better seismic performance.In order to further explore the force performance of the node,this paper is based on the large-scale general finite element software ABAQUS to conduct a numerical simulation analysis of the force performance of the assembled node.The main research contents and main results are as follows:(1)This research group conducted an experimental study on the prefabricated frame beamcolumn concealed corbel angle steel connection node under low-cycle repeated loads,including1 cast-in-place specimen and 3 prefabricated specimens.The results show that the joint has good seismic resistance.performance.(2)The finite element model of the fabricated node was established,and simulation research was carried out.One traditional cast-in-place node and three fabricated beam-column connection nodes were simulated separately,and the simulation results were compared with the test results on the failure form,hysteresis curve and skeleton curve.It is found that the simulation results are basically consistent with the experimental results in all the above aspects.At the same time,the influence of the test parameters on the mechanical performance of the specimen is verified,which shows that the modeling method of the fabricated node is reliable.(3)On the basis of verifying the reliability of the modeling method,the influence of factors such as axial compression ratio,concrete strength,steel cover thickness,angle steel thickness,additional rib thickness and bolt diameter on the seismic performance of the joint was simulated and analyzed,and the study found : The axial compression ratio has almost no effect on the seismic performance of the specimen;Increasing the strength of concrete and the thickness of the steel cover can increase the bearing capacity and energy consumption of certain specimens;The thickness of the angle steel has a great influence on the negative force performance of the test piece.With the increase of the thickness of the angle steel,the negative bearing capacity and stiffness of the test piece are greatly improved,but the positive direction changes little;The bearing capacity,stiffness and energy dissipation capacity of the test piece increase with the increase of the bolt diameter,but the increase is slower when the diameter reaches 22 mm.By adjusting the appropriate parameters,the force performance of the fabricated joint can basically reach the equivalent of the cast-in-place joint.