Numerical Simulations Study On Seismic Behavior Of The Resilient R C Frame Structures Based On C-shaped Shell Members

The shape of a C-shaped shell member is similar to the commonly used steel tape.Due to its outstanding mechanical properties after special treatment,it is widely used in structural engineering.Based on the resilient performance of C-shaped shell,the research group proposed a new type of resilient frame structure system by combining it with viscoelastic dampers,and applied the C-shaped shell to the frame structure where the bottom layer is the weak layer,which can achieve the quick repair of the weak bottom layer after an earthquake.By means of experimental tests,finite element simulations and theoretical analysis,this paper performs an exploratory study on the new type of resilient frame structure system.(1)To understand the basic mechanical properties of the C-shaped shell members,the anti-lateral performance tests and the axial compression tests after large deformation were conducted in this study,the equations of the lateral buckling loads along the strong and weak axes of the C-shaped shell members are established and the restoring force models of the strong and weak axes of the C-shaped shell members are fitted.(2)To establish the resilient frame model with different stiffnesses ratios between the bottom layer and the adjacent layer,a resilient system,where the core is the C-shaped shell member,is applied to a five-layer frame structure using finite element analysis software ABAQUS based on the mechanical property test results,and finite element dynamic elastoplastic simulation analysis is also conducted.The simulation results show that: When the stiffnesses of the bottom layer and adjacent layer are relatively large,the structural failures are completely concentrated on the bottom layer,and the existence of the resilient system can improve the seismic performance of the structure and perform the rapid restoration of the weak layer in the bottom layer.Through the rational design,the structure can achieve the seismic fortification objectives of remaining undamaged after minor earthquakes and being able to be restored after neutral and major earthquakes.(3)A model of the resilient frame structure system was developed according to the similarity theory and the shaking table tests were also performed.The results of the shaking table tests show that: the seismic performance of the structure can be improved by setting a C-shaped shell based resilient system.Subjected to strong vibration,the bottom layer of the structure is seriously damaged.There is no obvious deformation on the surface of the C-shaped shell and its lateral stiffness and vertical bearing capacity do not decline significantly.After the vibration,the damaged concrete columns can be quickly replaced to restore the seismic performance of the structure under the support of the resilient system.(4)The results of the shaking table tests are compared with the results of the finite element analysis.The results show that they are relatively consistent,which proves the validity of the modelling method used in this paper.