Experimental Study On The Seismic Behavior Of New-type Joints In Steel Adding Storey

With the development of population of China, the housing area of each people is decreasing and the pressure is much more severely. Adding with light steel structure storey can effectively increase the building usable floor area and alleviate the housing pressure. In domestic the light steel adding storey has gradually gained extensive application, this structure could save the engineering cost and construction period, can’t affect the structure of normal use, and so on. For a long period of time, the technique of structural with steel is in a state of chaos without to follow, as the connection of two kinds of different materials of prefabricated and the key parts of the structure is very difficult to guarantee the seismic property of the nodes, so that the node processing become the key to the success of the light steel adding storey engineering. At present, a lot of scholars research about of the adding layer in the feasibility and the software simulation analysis on this stage. The software simulation analysis deviated from the practical engineering and lacks of reliable data of experimental, the research of this aspect is still far from mature in our state, Therefore, the engineering research of frame structure with light steel adding storey enter into a hot spot.Based on a actual engineering of adding stories with light-weight steel structures on a three-layers of building, traditional plant steel, strengthen with carbon fiber reinforced plastic sheet or Steel plate and connection transformation forms, four types of nodes between a concrete frame and the added light steel stories were investigated under low-cyclic loadings to research the seismic performance.Compare with the performance of the test specimens was evaluated in terms of failure mode, hysteretic behavior, skeleton curves, stiffness degradation and energy dissipation and ultimate shear capacity of the node etc of the four types of nodes.The results show that:the traditional plant steel due to the interior joint shear failure, the others joints fail due to the plastic hinges formed at the beam end. During the test of low-cyclic loadings the plant steel, bolted and welded joints are favorable; The performance of nodes traditional the plant steel is the least,The hysteretic curves of the node of strengthen with Steel plate materials are plump, and the indicates that significant resistant capacity and satisfactory energy dissipation ability. The node of strengthen with carbon fiber materials can mitigation the producing of crevice and the yielding load; the joint be transformed connection form can improve the connection performance of the node. The construction technique of transform the connection forms of the type of nodes simple and convenient,and improve the Stiffness in the largest range.