Study On Seismic Behavior Of Concrete-filled Square Steel Tubular-Steel Beam Frame

The familiar connection with inner diaphragms has a defect that is the quality of the weld between the beam flange and column plate difficult to be achieved, in structure of concrete-filled steel rectangular tubular.In this paper, a damaged frame of this research group experimented has been reinforced. Aimed at the welding problem of the former experiment, this study put forward a reinforced method of reinforce the joint and reduce the beam of shifting away plastic hinge from column face. In this study the character of the reinforced frame's failure has been researched and the capacity of loading, distortion, energy absorption and properties of rigidity degradation of the twice experimentshave been compared; At last, a model of this reinforced frame of concrete-filled squre steel column and steel beam has set up by Nonlinear Finite Element Method(NFEM). It studied the joints yield character of the model and the whole model's energy absorption, and so on.In this paper, it is indicated that the reinforced frame has higher horizontal capacity and better deformation under cyclic loading than the former experiment; the frame's abilities of seismic energy dissipation has resumes after reinforced; the reinforced method is reasonable.It is shown that theoretic hysteresis curve of the reinforced frame by NFEM is very plump, and the frame model has a good capability of energy absorption; The dimension of the beam reduction is small a little, it has no evident effect that make the reduction position yielded at a first time, but it can help to the plastic hinge development in steel beam. This study suggests that increase the reduction dimension of the end of beams or add a steel plate at the column flange of the joint.