Experimental Study On Static Performance Of H-Section Column End Plate Connection Of Castellated Beam

Steel frame castellated beam H-section column end plate connection has the advantages of convenient construction,easy assembly and green energy saving,while the beam web opening is convenient for crossing the pipeline,reducing the structural self weight and improving the seismic performance of the structure.In the process of research on H-section column end plate connection of castellated beam,it is found that the connection can relieve the stress concentration at the hole angle of castellated beam to a certain extent,and the reasonable opening of castellated beam can make the plastic hinge at the connection move out,so as to avoid the brittle failure of the beam column connection.At the same time,it is found that the H-section column end plate connection of castellated beam has good energy consumption performance,which shows that the connection has good application At present,there are few researches on its mechanical properties at home and abroad.In this paper,the monotonic loading tests of H-section column end plate connections of three different parameters of hexagonal castellated beams are carried out by means of experimental research,theoretical analysis and numerical simulation.The load displacement curve,initial rotational stiffness,ultimate bearing capacity,ultimate rotation angle and failure mode of the beam column connections under monotonic loading are obtained.At the same time,the column web,end plate and At the connection of column flange,the load-strain curve around the first hole of castellated beam near the column end is plotted.The finite element model of H-section column end plate connection of castellated beam is established by using numerical simulation software,and the accuracy is ensured by comparing with the test results.The opening rate,opening distance and opening number of H-section column end plate connection of castellated beam are taken as parameters to establish 55 H-section column end plate connections of castellated beam Connect the model,analyze the influence of the above parameters on the initial rotational stiffness,ultimate bearing capacity and failure mode of the H-section column end plate connection of the castellated beam,calculate the initial rotational stiffness of the H-section column end plate connection of the castellated beam according to the existing calculation method of the initial rotational stiffness of the solid web beam column connection of the end plate connection,and compare the calculated results with the test values and simulation values,and find the opposite end of the opening on the beam Combined with the phenomenon and relevant data in the test,the calculation model of the H-section column end plate connection stiffness of the castellated beam is simplified,and the calculation method of the initial rotation stiffness of the H-section column end plate connection of the castellated beam is obtained.The results show that the initial rotational stiffness of H-section column end plate connection increases with the increase of end plate thickness;the larger the opening ratio ofH-section column end plate connection with a certain end plate thickness and a certain opening distance is,the more plastic hinge will be formed at the end of the beam;the ultimate bearing capacity of the connection is related to the failure mode of the connection,and under the same failure mode,the opening ratio is between 50% and 70% With the increase of the opening rate,the ultimate bearing capacity decreases slightly;when the opening distance of the H-section column end plate connection with a certain opening rate and a certain thickness of the end plate is less than 0.5 beam height,the opening rate of 50% will also form a plastic hinge.The ultimate bearing capacity of the connection is related to the failure mode of the connection.Under the same failure mode,the opening distance between 0.5 beam height and1.5 beam height is between 0.5 beam height and 1.5 beam height With the increase of the opening distance,the ultimate bearing capacity increases slightly.It is suggested that in the design of H-section column end plate connection of castellated beam,the thickness of the end plate should be greater than the thickness of the column flange,the opening rate on the beam should not be greater than 65%,and the opening distance should be between 0.75 beam height and 1 beam height.In this paper,the calculation formula of the initial rotational stiffness of the end plate connection castellated beam column joint is given.The comparison between the calculation formula and the actual value shows that the accuracy of the calculation formula is good.