Seismic Analysis Of Steel Frame Structure Based On New SMA-buckling Restrained Brace

Shape memory alloys(SMA)have been a research hotspot in the field of materials in recent years.Because of their unique shape memory effect and good self-reset ability,they have been favored in the field of building seismicity.They are often used in dampers to provide a certain degree of structural recovery.Force to reduce the residual deformation of the structure.Buckling Restrained Brace(BRB)is a new type of support member with strong energy consumption capacity.By restraining the core unit from restraining the core unit,the energy consumption of the core unit is increased compared to the pure steel support.Capacity,so that the buckling restraint support can yield under tension and compression,so as to obtain better hysteretic energy dissipation capacity.Therefore,this paper proposes a new type of SMA stranded-buckling restrained support based on the two,which combines the excellent energy dissipation capacity of buckling restrained support and the good self-centering ability of SMA stranded wire,and applies it to steel frame structures.In order to improve the shock absorption capacity of the structure.The main contents of this paper include the following aspects:(1)A series of experiments were conducted to study the mechanical properties of shape memory alloys,including the effects of strain amplitude and loading frequency on the single-turn energy consumption,equivalent secant stiffness,and equivalent damping ratio of SMA strands during loading and unloading.(2)The Graesser & Cozzarelli model is summarized,and the Graesser & Cozzarelli model is improved based on the mechanical properties test of the SMA strands,so as to overcome the shortcomings of SMA that cannot be expressed well in the martensite hardening stage in the model.The improved model was simulated by the Simulink toolbox,and the experimental and simulation results were compared to verify the correctness of the improved Graesser & Cozzarelli model.(3)A new type of SMA stranded-buckling restrained brace is introduced,its structural form and working principle are introduced,and its hysteretic performance is simulated by the finite element software ABAQUS.The hysteretic performance of the new SMA stranded-buckled restrained brace is analyzed.(4)A 12-story steel frame structure model was established using SAP2000.Three types of seismic waves under the second-class site were selected,and the pure steel frame structure under the action of rare earthquakes and rare earthquakes was equipped with a new type of SMA stranded-buckling restrained braced steel.The top layer displacement response,base shear force and interlayer displacement angle of the frame structure are analyzed,and the new SMA stranded-buckling restrained brace is used to analyze the energy dissipation capacity under different earthquakes.