Study On The Seismic Performance Of High-rise 3D Parking Structures With Steel-lead Composite Fractional Energy Dissipated Buckling-restrained Braces

With the development of economy,there is a great contradiction between parking facilities and parking demand,and"parking difficulty"has become a major problem affecting the development of urbanization and people’s happiness of life.High-rise three-dimensional parking structure has the characteristics of small occupation area,high space utilization rate,convenient vehicle access and so on,and has become the first choice to alleviate the problem of"difficult parking"in cities.Compared with the general steel frame structure,the high-rise stereo garage structure is a typical high flexible structure.Generally,the cylindrical steel frame structure is adopted.The height and width of the structure are high and the ratio of height and width is large.To facilitate vehicle access,three-dimensional garage structure within the rigid floor slab is not set,with the increase of the layer number,significant action of horizontal loading,the lateral structure increased significantly,while the peripheral frame beam with no support of floor slab structure,makes the column and beam structure plane constraint is insufficient,the frame under earthquake is easy to generate a larger global or local deformation.The conventional buckling-restrained braces(BRB)are usually in elastic state under frequent earthquakes without dissipating energy.In order to solve thi s problem,a steel-lead composite fractional energy dissipated buckling-restrained braces(SLBRB)was proposed by cutting holes in the one-character buckling-restrained braces and combining them with lead cores.Primarily,the working principle and structure of SLBRB are introduced.Secondly,the finite element analysis of SLBRB modeling was carried out using ABAQUS finite element software.Finally,the influence of three key parameters on the mechanical properties of SLBRB is studied,including the area of lead core,the layout of lead core and the ratio of lead diameter to the opening width of core plate(diameter-width ratio).The results show that the structure design of SLBRB is reasonable,and the lead cores and the core steel plate can work together.The hysteresis curve is full,and the energy dissipation capacity of grading is good.Finally,the recommended key parameters of SLBRB design parameters are given:the value of lead core area should ensure that F_d/F_c is less than0.229;it is suitable to use single lead core arrangement form;the diameter-width ratio should be equal to or less than 1.With the development of economy,there is a great contradiction between parking facilities and parking demand,and"parking difficulty"has become a major pro blem affecting the development of urbanization and people’s happiness of life.High-rise three-dimensional parking structure has the characteristics of small occupation area,high space utilization rate,convenient vehicle access and so on,and has become t he first choice to alleviate the problem of"difficult parking"in cities.Compared with the general steel frame structure,the high-rise stereo garage structure is a typical high flexible structure.Generally,the cylindrical steel frame structure is adopt ed.The height and width of the structure are high and the ratio of height and width is large.To facilitate vehicle access,three-dimensional garage structure within the rigid floor slab is not set,with the increase of the layer number,significant action of horizontal loading,the lateral structure increased significantly,while the peripheral frame beam with no support of floor slab structure,makes the column and beam structure plane constraint is insufficient,the frame under earthquake is easy to gene rate a larger global or local deformation.Then,based on the finite element model of 14-story steel-lead composite stage energy dissipated buckling brackings and the selected three rare seismic waves,such as El-Centro wave,Taft wave and artificial wave,the corresponding seismic control effects of different steel-lead composite stage energy dissipated buckling brackings on structures are analyzed.Based on the peak displacement response of the structure in X and Y directions,the peak displacement respons e of each layer in X and Y directions,the peak shear Angle response of the parking area and the peak shear response of the bottom of the structure,an arrangement scheme with a higher control rate on the dynamic response of the structure is obtained.On th is basis,the seismic time-history analysis of different layers of steel-lead composite graded energy dissipated buckling restrained braces for three-dimensional parking structures is carried out to verify the universality of the proposed layout scheme.Finally,the energy response analysis is made for the three-dimensional parking structure of steel-lead composite classification energy dissipated buckling restraint braces from the perspective of energy,and the energy dissipation and shock absorption effect of steel-lead composite classification energy dissipated buckling restraint braces on high-rise three-dimensional parking structure is quantitatively analyzed.The research results in this paper provide a new type of steel-lead composite energy dissipation buckling restraint braces and provide a theoretical basis for the application of buckling restraint braces in high-rise parking structures.