Analysis Of Influence Of Beam-column Joint Connection Mode On Seismic Performance Of Braced Frame Structure

Because of its excellent performance,steel structure is widely used in industry,civil buildings and structures.Because its construction is simple and fast,the hinged connection between beam and column is widely used.In the frame with the beamcolumn hinged connection,in order to solve such problems as lack of enough stiffness,we need to set supports in order to improve the stiffness of the whole structure.In people's subjective consciousness,people think that the resistant-lateral stiffness of beam-column rigid connection is greater than the beam-column hinged connection,and the structure with brace is stronger than the structure without brace;At the same time,people also think the structure has bigger lateral stiffness,its response of base shear force will be bigger.However,the analysis to the node rigidity and the contribution of brace to the lateral stiffness of the structure is less,at the same time,the research to the overall seismic performance of the braced-articulated frame structure is not thorough enough.In order to further study the aseismic performance of the braced-articulated frame structure,the following aspects are mainly done in this paper:First of all,do some theoretical derivation,which includes the contribution of connection stiffness of beam-column joint and the brace to lateral stiffness of the frame;At the same time,according to the calculated length method,do some derivation which is the calculation formula about the calculated length of the below column influenced by rigid joint or hinged joint.The effect of joint stiffness and bracing arrangement on the lateral stiffness of frame is explained in principle.Secondly,Building up respectively braced-hinged frame,support-rigid frame and the pure frame space model,the same frame model have three layers and eight layers.In the frame space model,we selected the typical horizontal frame,using the finite element analysis program to push-over the model.Through analysis and comparison of the three-layer and eight-layer structure of different joints,there is no brace arrangement of the push-over analysis results,the evaluation of node connection form and have no support arrangement for the impact of the seismic performance of the frame structure.Finally,the modal analysis of the three-layer and eight-layer analysis model shows that the effect of the support on the low-order vibration mode of the whole structure is greater,have less influence to stiffness of joint connection stiffness.The two factors have less influence to high order mode.The elastic time-history analysis and elasticplastic time-history analysis of the three-layer and eight-layer analysis models are carried out by the finite element program.We analyze the different factors,such as the joint stiffness or different brace arrangement of multilayer structure and high-rise structure,and contrast to the top displacement,the base shear force,the maximal layer to layer shear force,the maximal layer to layer displacement and displacement angle of the frame structure under the earthquake action.We show the clear results on the seismic performance of braced-articulated frame structure and rigid-braced frame structure.