Research On The Seismic Property And Triple Seismic Fortification Lines Work Mechanism Of The Multi-ribbed Composite Wall

ABSTRACT:Multi-ribbed composite wall structure is a new type of prefabricated concrete structure system,characterized by saving energy,low weight,high strength,good aseismic performance and can adjust stiffness as need.The study on this structure have achieved great progress in both theoretical research and engineering application during the past twenty years.Based on the prior research,the concept of multi-ribbed-energy dissipation composite wall is put forward.And the seismic performance,calculation model,triple fortification lines work mechanism,nonlinear numerical analysis method and other problems of the composite wall are researched in this thesis.The main works of the thesis are as follows:(1)Low cycle reversed loading test are conducted on 3 multi-ribbed composite wall specimens with different structural forms and filling condition.According to the experimental phenomena the failure process and failure pattern of different wall is summarized,the seismic performance including bearing capacity,stiffness,ductility,hysteretic curve characteristic,energy-dissipation capacity,stiffness degradation and strength degradation time-varying law are researched.The main factors which affect the wall seismic performance are analyzed.Through the point contact multi-ribbed composite wall experimental result,the triple fortification lines work mechanism is analyzed.(2)The refinement numerical model of multi-ribbed composite wall structure"fiber bar element + layered shell" model is put forward,which can simulate the whole work process of multi-ribbed composite wall structure.According to this model,the nonlinear hysteretic performance of multi-ribbed composite wall under cyclic loading is simulated.By comparing with the experimental results,the model can simulate more precise nonlinear characteristics of multi-ribbed composite wall,the calculated hysteretic curve and test curve are anastomotic.In addition,the main factors affecting the multi-ribbed composite wall limit bearing capacity is analyzed.The relationship of multi-ribbed composite wall seismic performance and the main influence factors is received.(3)According to the multi-ribbed composite wall structure form,combined with the experimental results,the triple seismic fortification lines work mechanism of multi-ribbed composite wall is analyzed.The research indicate that,through the adjustment of restoring force characteristic parameters of three seismic fortification lines,three phases failure mode of multi-ribbed composite wall structure can be achieved.According to the working mechanism of multi-ribbed composite wall in different stages,the multistage calculation models are proposed,and the formulae is given to calculate the ultimate bearing capacity of the multi-ribbed composite wall.By the multistage calculation model,the stiffness calculation formula in different stage feature point is put forward,and the stiffness attenuation rule of the wall during the whole stessing process is researched.(4)The concept of multi-ribbed-energy dissipation composite wall is put forward.Cyclic loading tests are conducted on 3 steel energy dissipator specimens,the bearing capacity,stiffness,energy dissipation performance and restoring force characteristic parameters of energy dissipator are received.By numerical method,the energy consumption performance of multi-ribbed-energy dissipation composite wall is researched.The energy dissipation mechanism and the principle of damage reduction of multi-ribbed-energy composite wall is preliminary researched,and the basic equations of energy method and the damage reduction control design procedure applied to this structure is proposed.In conclusion,the seismic performance and triple fortification lines work mechanism of the composite wall are researched in this thesis,and the refined multistage calculation model are proposed.Meanwhile,the concept of multi-ribbed-energy dissipation composite wall is put forward,and the energy consumption mechanism is researched.The research in this thesis provide theoretical reference and design basis for the further research and engineering application of multi-ribbed composite wall structure.