1. School of Civil Engineering, Central South University, Changsha 410075, China; 2. Hunan institute of nonferrous geological exploration and research, Changsha 410015, China
Abstract：In order to verify the destruction characteristics and seismic performance of the joints composed of concrete-filled steel tubular lattice column and composite box girder in the mega-composite structure system, the three different-connection types of joint specimens, they are single limb bracing, cross bracing and diaphragms for the core area of the joints, have been tested under low cyclic loading testing. According to the comparison of the results, load-displacement hysteretic curves and skeleton curve were obtained. Moreover, main parameters for estimating seismic behavior of connection with composite joints were studied, such as load-carrying capacity, ductility ratio, degradation laws of strength and stiffness, energy consumption index and equivalent viscosity coefficient. Meanwhile, ABAQUS nonlinear finite element models were used to analyze the seismic behavior of the connection and the results were also compared with the experimental results. The research shows that: analytical results agree well with experimental results and the theoretical analysis proves to be correct. Meanwhile, all of the three joint specimens have great positive displacement ductility and the reverse displacement ductility is not as much as the positive displacement ductility. With the connecting of joints reinforced, the joints' yield displacement gradually decrease and the bearing capacity and displacement ductility of the joints gradually increase. In addition, better energy dissipation capacity was showed in the joint connection with diaphragm than others. Those properties can make connection consume much energy in earthquake and meet much better the need of seismic design.
2014, Vol. 33 
