Experimental Study On Seismic Behavior Of H-type Steel Energy Dissipation Joint Of Assembled RC Frame

The prefabricated concrete structure has the advantages of short construction period,high product quality,low energy consumption,and low environmental pollution.It is an inevitable choice for the sustainable development of the construction industry.An important factor restricting the development of prefabricated concrete structures is the connection of nodes.For the fabricated frame structure,the beam-column joint is the top priority,which directly affects the seismic performance of the fabricated concrete structure.In this paper,an H-shaped steel energy dissipation connector is designed and used for the connection of prefabricated RC frame concrete beam-column members.The mechanical properties of the connector are studied in detail using the experimental research,numerical simulation and theoretical analysis research methods.The main research contents and conclusions are as follows:(1)Five H-shaped steel energy dissipation connectors were designed,one of them was subjected to monotonous loading test,and the remaining 4 specimens were subjected to low-cycle reciprocating loading test.Mechanical properties such as failure form and bearing capacity,stiffness,hysteresis,ductility and energy dissipation capacity under size and load conditions.The test results show that when the test piece is subjected to pure shear load,the crack first appears in the diagonal direction of the opening of the web,and the crack further extends to the direction of the flange side as the load increases;when the test piece is subjected to bending shear When the load is applied,the flange yields first,and cracks gradually appear and gradually extend to the web along the diagonal direction of the opening as the load increases.Increasing the size of the flange can effectively improve the bending load-bearing capacity and deformation capacity of the energy dissipation part,and the energy dissipation capacity can also be significantly improved.(2)ABAQUS finite element software is used to model and calculate the assembled RC frame H-shaped steel energy dissipation node connectors,and the rationality and reliability of the model are verified by comparing with the test results.On this basis,the test piece span is high The influence factors such as the ratio,flange width,flange thickness,web thickness,load bending-shear ratio and so on were extended and analyzed,and their influence characteristics on the bearing capacity and failure mode of the specimen were discussed.The results show that the factors that have a greater impact on the shear capacity of the connector are the high-span ratio,the thickness of the web,and the width of the flange.Changing the thickness of the flange has little effect on the shear capacity of the connector;at the same time,The stress state(bending shear ratio)of this connector has a significant effect on its failure mode.When the bending-shear ratio is 0(pure shear load)or less,the deformation of the specimen is mainly shear deformation,and the failure form is shear failure;when the bending shear is relatively large,the deformation of the specimen is mainly bending Deformation is dominant,and the failure form is bending shear failure.(3)Analyze the stress mechanism of the H-shaped steel with web openings,put forward a simplified calculation model of the connector and a more reasonable bearing capacity calculation formula,and propose a simplified restoration force model of the connector when the formula is modified and optimized.The skeleton curve of the simplified restoring force model obtained is basically consistent with the skeleton curve measured by the test,thus verifying the correctness of the theoretical formula and the simplified restoring force model.Afterwards,a non-linear finite element software perform-3D was used to simulate and analyze the assembled concrete frame with cast-inplace nodes and energy-consuming connectors.The analysis obtained the assembled concrete frame with energy-consuming nodes in terms of rigidity,bearing capacity and ductility.Both are slightly better and have better dissipation capacity under the action of earthquake.