Pseudo Dynamic Experimental And Theoretical Analysis On Concrete-filled Double Skin Steel Tubular Frame With Wall-type Metallic Damper

In recent years,steel-concrete composite structures have been developed and widely used,and various new steel-concrete composite structures have emerged in endlessly.Concrete-filled double skin steel tube(CFDST)structure is composed of teel tubes whose inner and outer section centroids coincide,and the concrete is poured in the steel tube sandwich to achieve cooperative work.Compared with concrete-filled steel tube,it can reduce the weight of the structure while maintaining the bending stiffness,bearing capacity and fire resistance.Wall-type metallic damper has good hysteretic characteristics,simple structure and convenient fabrication.The combined structure of CFDST and walltype metallic damper has broad application prospects.However,there is currently a lack of research on CFDST frame with wall-type metallic damper.In order to understand the performance of this type of frame,this paper carries out the seismic performance and vulnerability analysis of CFDST frame with wall-type metallic damper,which has important theoretical value and engineering significance.The main research contents are as follows:(1)This paper designs a CFDST frame to prove the rationality and reliability of the prototype frame structure,and divides the numerical substructure and the experimental substructure through substructure interaction method;According to the test substructure,a two-story single-bay CFDST frame is tested,and the failure mode of the key parts of the test sub-structure is obtained.The analysis model of this frame is established by using Open Sees finite element analysis software,and the seismic performance of the prototype frame is evaluated by combining the test substructure and the numerical substructure,By comparing the displacement time history curve and load time history curve of each floor under different levels of earthquake,it is revealed that this frame has good deformation capacity and seismic performance.(2)A method of energy dissipation and damping with wall-type metallic damper is proposed.The finite element analysis model of CFDST frame with wall-type metallic damper is established.The performance indexes of the frame such as displacement angle and residual displacement angle between different fortification standards are revealed.The results show that the wall-type metallic damper has good lateral deformation control ability for the frame,and this kind of frame has good seismic performance and deformation ability under the seismic action of all levels of fortification standards.(3)Based on the incremental analysis method,probabilistic fragility analysis of noncollapse and collapse states of CFDST frame with wall-type metallic damper was conducted to learn the probability of exceeding the various damage states of such frames under the action of ground motion and to assess the collapse resistance of the frames.The results show that this frame has good collapse resistance and has a rich reserve of collapse resistance,which is feasible and reasonable for seismic applications in practical projects.