| As a new system of building structure,SRC composite structure are significantly better than the ordinary RC structure in such aspects as strength,ductility,energy dissipation capacity,which has a good seismic performance.Nodes act as power transmission hub and belong to the key part of the frame structure.In most of the earthquake,many buildings collapsed due to node joint serious damage and a single beam itself damage slightly,which illustrates the normal work of the node is to ensure the premise of the whole structure safety.In this paper,we should find out the SRC nodes mechanism and the power transmission way through the experimental study and theoretical analysis,get a reasonable calculation model and structural measures and provide reliable reference for the application of SRC composite structure in the engineering practice.In this paper,start study mainly aiming at the SRC column-steel beam node which is one type of SRC nodes,set axial compression ratio as the main factors,make four nodes’ low reversed cyclic loading test and specimens X reinforced in one of the core configuration discussing if it can improve the crack resistance of concrete.Experimental results show that the hysteresis curve of four nodes are relatively full,no obvious pinch approach phenomenon,which reflects the good ductility energy dissipation capability.The destruction of the node form mainly shear failure and although the existence of axial pressure can inhibit and delay the appearance of concrete cracks,but excessive axial pressure envoys point shear failure into beam end bending failure.Of concrete early crack load well validated in core X reinforcement configuration can delay the occurrence of cracks and effectively improve the crack resistance of concrete.According to the experimental data,compare the shear values with the theoretical value and propose to the relevant specification of shear bearing capacity of modification.By using the finite element software ABAQUS numerical simulation analysis was carried out on the four specimens of the test.Results show that the test values arein good agreement with the theoretical value as a whole,and illustrates the ABAQUS to simulate nonlinear behavior has the very good feasibility,meanwhile,the structure can better simulate the macroscopic damage.On this basis,start finite element analysis on the strength grade of concrete,reinforcement ratio,stiffener thickness,web plate thickness of four parameters to discuss their impact on the bearing capacity of the joint.Through comparison and analysis,we find that increasing the thickness of the web is the most direct and effective way to improve the bearing capacity of joints. |
