Static And Dynamic Analyses Of Dual Systems Of Concentrically Chevron Braced Frames

Interacting system of concentrically braced and moment resisting frames is one of the commonly used dual systems resisting lateral forces. It is widely used in tall buildings as an effective and economic seismic structure system. While this system is considered inadequately in design, it may suffer extensive damage under strong ground motion during the seldomly occurred earthquakes.The slenderness ratio limitation and the manner in checking bearing capacity of the bracing member are key factors to the seismic performance of this system. Experimental researches indicate that the bracing members with larger slenderness ratios also have better low-cycle fatigue resistance and energy dissipation capacity. Our national codes are keeping a strict hard on the slenderness ratio limitations of bracing members, and they strengthen the bracing members in checking their bearing capacity. This measure may lead to larger seismic response and is not an economical design. On the contrary, the design of Special Concentrically Braced Frames (SCBF) is saving and reasonable.Using the SAP2000 finite element program, structure models are designed according to different slenderness ratio limitations and manners in checking bearing capacity of the bracing member firstly in this paper.Using the ABAQUS/standard finite element program, considering geometric or material non-linearity,elastic-plastic static analysis,elastic and elastic-plastic time-history analyses of the models are performed. The effects of different slenderness ratio limitations and manners in checking bearing capacity of the bracing member on the weight of steel, the stiffness, the lateral ultimate load-carrying capacity, the shear-bearing ratio of moment frame, the absolute acceleration peak value of top floor , the displacement peak value of top floor, the relative displacement, the displacement and the shear force of structure bottom are compared.At last, in order to check their validity, corresponding models are built according to the two kind of manners explained by America experts and our nation codes on checking shear-bearing capacity of moment frame, the shear-...