Research On Seismic Performance Of Assembled Bolt Connection Reinforced Concrete Column-steel Beam Composite Frame Joints

Reinforced concrete column-steel beam combined frame structure,because it can give full play to the mechanical properties of reinforced concrete column and steel beam,has gradually been used as a beneficial supplement to the existing reinforced concrete frame structure and steel frame structure and other structural systems.In this paper,the following research work is carried out to ensure the convenience of construction and good seismic performance of reinforced concrete column-steel beam composite frame joints:1.Three new types of assembled bolt-connected reinforced concrete column-steel beam composite frame joint types are proposed.The structural characteristics of the joint are:the concrete is restrained by the steel plate hoop to improve the compressive strength and ductility of the concrete;the built-in stiffening webs and horizontal stiffeners of the steel plate hoop improve the load bearing of the joint while taking into account the scientific and effective force transmission mechanism;The steel parts can be welded in advance in the factory,and then concrete is cast to form a combined joint,and finally assembled with steel beams on site by high-strength bolts,which can effectively ensure the construction quality of the joint,improve the construction schedule and reduce the construction cost.2.Design and manufacture three 1/2-scale assembled bolt-connected reinforced concrete column-steel beam composite frame joints and conduct pseudo-static test.The test results shows that:cover plate or angle steel bolt connection based on plastic hinge outward movement construction measures all of them show the advantages of earthquake resistance;the widened flange single cover connection can ensure that the weld is not damaged in advance and the cover deformation energy consumption,showing higher strength and better ductility;the cover and angle steel bolt connection is easy to remove,Repair and replace the damaged components after the assembly structure can take advantage of this feature;3.The software ABAQUS was used to establish a finite element analysis model of assembled bolt-connected reinforced concrete column-steel beam composite frame joints,and the validity and accuracy of the finite element model were verified by two examples.The parameterized analysis results of the finite element model show that the bolt preload has little effect on the overall seismic performance of the node,and the initial stifness and ultimate load carrying capacity of the node with different preloads are basically equivalent;the angle steel thickness affects the stiffness and strength of the node Larger;the thickness of the joint steel plate hoop and the splicing web have a certain effect on the joint stiffness,but after reaching a certain thickness,the impact on the joint is reduced;setting stiffeners can significantly improve the joint stiffness and strength,but increasing the thickness of the joint The influence of the joint performance is not obvious;the steel beam is provided with a long round hole,and the joint slips obviously during loading.This feature can be used in the design of energy dissipation and shock absorption;the axial compression ratio of the column has a limited impact on the joint performance.The increase of the pressure ratio can reduce the cracking of the concrete in the node area to a certain extent;...