FEM Analysis On Behavior Of Joint Between Concrete Column And Steel Beam Base On Tests

Reinforced concrete column and steel beam composite frame(RCS), composed of reinforced concrete column and steel beam, is a newly low cost and highly efficient structure for its economical utilization on the characteristic of steel and reinforced concrete. It is necessary and meaningful to know the function of the joint, improve construction details of the kind of connections. It helps to assure the safety of the composite structures and widen the use of RCS composite structures through study on the mechanical behavior of the joint.Six joints of concrete column-steel beam combination frame had been design in the paper. For the Through Beams joint of reinforced concrete column and steel beam, taking some constructional measures as the main three parameters, such as setting horizon stirrup in the joint core, slotting in the flange girth of the steel beam and welding portion longitudinal reinforcement, setting little structural section and steel lattice in the side of the core of the joint in the column, finite element (FEM) analysis on behavior of three joints between concrete column and steel beam were done. For the Through Columns joint of reinforced concrete column and steel beam, taking some constructional measures as the main three parameters, such as the number of high-strength bolts, high-strength bolts layout, high-strength connection, the same FEM analysis on behavior of three joints between concrete column and steel beam were done. And on the basic of experimental results, the capacity and aseismic behavior of joints between concrete column and steel beam were studied. According the analysis we can obtain several conclusions:1. For the through beams joint of reinforced concrete column and steel beam, slotting in the flange girth of the steel beam and welding portion longitudinal reinforcement, setting little structural section and steel lattice in the side of the core of the joint in the column, can affect the function of the joint in large degree. The capacity of the joints was large and seismic behavior of joints was good. If the web plate of steel beam isn't buckling early, it is very suitable to use the through beams joints in the composite structures.2. For the through columns joint of reinforced concrete column and steel beam, FEM analysis results show stress concentration in connection between steel beam and connecting plate, and experimental results also show the failure was occur in the welding seam between steel beam and connecting plate. So the quality of the welding seam is very important to the function of the joint.3. The high-strength bolts connections between steel beam and connecting plate can affect the function of the through columns joint of reinforced concrete column and steel beam in certain degree. The big effective cross-section area of high-strength bolt should be chosen under satisfying detailing requirements of the joint. It can improve the capacity and aseismic behavior of the through columns joint under not-increasing the cross-section of steel beam or the number of high-strength bolts.4. FEM analysis results and experimental results show the through beams joint and the through columns joint belong to reinforce joint. The joint's damage form was the beam end failure. Under cyclic loading, the core of the joint and the column is still in the flexibility state, and it is suitable for design requirement, such as reinforce column and weak beam, reinforce joint and weak component.