Study On Mechanical Properties And Design Method Of Steel-connected Concrete Beams

In the fabricated shear wall coupling beam,the coupling beam plays an important role in the bearing capacity,energy dissipation capacity,ductility and deformation of the overall structure,and different joint forms also have an important impact on the seismic performance of the structure.To this end,this paper compares the design forms of other coupling beams,arranges steel plates at the joints of the coupling beams,and makes full use of the synergistic shearing effect of steel plates and concrete to improve the seismic performance of the coupling beams.The assembling structure and connection method of three kinds of fabricated shear wall coupling beams are proposed,which are connected by I-beam,U-shaped steel bar and arched steel plate.Based on the finite element analysis software ABAQUS,the finite element model of the experimental shear wall coupling beam is established,and the force process under the low-cycle reciprocating load is simulated and compared with the experimental results.The results agree well.The established finite element simulation method is feasible.On the basis of the size of the test model,the dimensions of the steel joints were designed,and the three types of steel-jointed shear wall coupling beams with I-beam(with and without filler),U-shaped steel bars and arched steel plates were established.The model,under the action of low-cycle reciprocating load,compared with the skeleton curves of cast-in-place test pieces and assembled test pieces,it can be seen that the bearing capacity of the three steel connections is relatively good and has good energy-consuming capacity,which meets the actual project.Claim.Based on the on-site construction requirements and the research contents of the current research group,the steel fiber(without filler)and U-shaped steel bars were selected to analyze and study the influencing factors of mechanical properties.For the I-beam(without filler)joints,11 fabricated shear wall and beam joint models were designed by changing the thickness of the flange,the height of the web and the yield strength of the steel.For the U-shaped steel bar connection joints,13 assembled shear wall and beam connection models were designed by changing the strength of the filler,the thickness of the groove steel plate and the number of steel bars.The stresses of the joints under low-cycle reciprocating loads under different influencing factors are simulated respectively.It can be seen from the simulation results that the hysteresis curves of the I-beam(without filler)connection and the U-shaped steel bar connection are full.There is no obvious pinch phenomenon,and the F-A skeleton curves of the corresponding joint nodes are extracted respectively.The yield load,ultimate load,displacement ductility coefficient,equivalent viscous damping coefficient and energy dissipation coefficient of each node are calculated.The effects of various factors on the skeleton curve and the stiffness degradation curve were analyzed.Through calculation,the theoretical shear values of the two stoe joints are far greater than the simulated values,indicatilg that the two steel joints have a high shear safety reserve and no shear damage.On the basis of different influencing factors,the calculation formulas of the flexural capacity of the joints of the I-beam(without filler)and the joints of the U-shaped steel bars are summarized respectively,and the steel connection nodes are redesigned for verification,which proves that the formula has High accuracy,which provides a theoretical basis for further design and research.