| With the rapid development of urbanization in China,the scale of urban construction and transformation is constantly increasing.Every year,more than hundreds of millions of tons of construction waste are produced,and waste aggregate is the largest amount of waste produced in the construction industry,where the disposal of waste aggregate has become a difficult problem.In order to achieve the secondary utilization of wast,e aggregate,the research group previously proposed a composite frame of Steel reinforced recycled concrete column-Steel beam(SRRC column-S beam),which can not only utilize waste aggregate,but also give full play to the performance advantages of steel.However,the mechanical properties and energy dissipation capacity of recycled concrete are different from those of ordinary concrete,which weakens the lateral displacement resistance and energy dissipation capacity of this kind of composite frame,and makes it easy to damage or collapse due to the material defects of this kind of composite frame under earthquake action.Existing studies show that the use of energy dissipation damping technology can effectively change the failure mechanism of the structure under earthquake action,enhance the seismic performance of the structure,and thus can reduce the damage of the structure under earthquake action.Therefore,this paper intends to adopt energy dissipation damping technology to enhance the seismic performance of the composite frame.Buckling-Restrained Brace(BRB)is a kind of energy dissipation damper with excellent performance,which can consume a large amount of seismic energy through its plastic deformation under earthquake action,and then reduce the damage of main frame structure.However,the impact of BRB on the seismic performance of the structure is closely related to the layout and design methods,and unreasonable design will increase the seismic response of the structure.Therefore,this paper analyzes the seismic performance of SRRC column-S beam composite frame with BRB components.The main contents are as follows:(1)The working principle and stability analysis of BRB members are introduced from the theoretical level,and the calculation formulas of equivalent stiffness and bearing capacity of BRB members are determined.(2)On the basis of the experiment,the SRRC column-S beam composite frame model was established by OpenSees software,and the simulation results were compared with the test results to verify the rationality of the selection of various constitutive models and the accuracy of finite element modeling.(3)Two anti-buckling support schemes with different layout forms are designed for SRRC column-S beam composite frame structure by adopting the seismic design idea based on stiffness contribution.OpenSees software is used to model them,and the seismic performance indicators such as hysteresis curve and skeleton curve,strength and stiffness,and energy dissipation capacity are compared and analyzed.The results show that the BRB members in the two BRB schemes can reach the yield state and exhibit good energy dissipation performance.The ultimate bearing capacity of the two schemes is more than 30%higher than that of the original composite frame.The energy dissipation coefficient and equivalent viscous damping coefficient of the original composite frame can be increased by more than 33%.(4)Using OpenSees software to build a 6-layer,12-layer and 20-layer BRB composite frame model,the time-history analysis under frequent and rare earthquakes was carried out.The variation rules of interstorey displacement angle,top-layer acceleration response,main frame layer shear,base shear and BRB axial force with bracing arrangement and anti-lateral stiffness ratio of BRB composite frame structure were studied.It turns out that,the interlayer displacement Angle and the shearing force of the main frame layer decrease,the acceleration response of the top layer and the base shearing force increase,and the axial force of the bracing increases with the increase of the lateral stiffness ratio.Compared with monoclinical arrangement,the Herringbone arrangement of BRB has smaller inter-storey displacement Angle,and it can effectively reduce the acceleration response of the top layer of the structure,make the shear force of the main frame layer decrease,and more floors of BRB reach the yield capacity,which is more conducive to reducing the damage of the main frame.(5)Both herringbone and monoclinic layout can be used when setting BRB member of multi-layer composite frame,it is suggested to use herringbone layout when setting BRB of high-rise composite frame.When the seismic fortification intensity is 8 degrees,the site category is Ⅱ,and the design earthquake group is the second group,the suggested value of the lateral stiffness ratio K of the multi-story BRB composite frame structure is 0.5～1.5,and that of the high-rise BRB composite frame structure is 0.5～1.0. |
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