Study On The Design Method Of Silt Shear Walls With Metal Dampers

To ensure that the structures have enough lateral stiffness,shear walls without opennings are often seen in many high-rise shear wall structures.However,damage always concentrates on the bases of theses shear walls after strong earthquakes,since seismic energy is mainly dissipated through the rotation of the plastic hinges formed on the bases.In order to eliminate the malpractice that shear walls without opennings dissipate seismic energy by inceasing post-earthquake damage of the key components,a new type of RC energy-dissipative shear wall,named slit shear wall with metal dampers(referred to as slit shear wall hearin),was proposed in this thesis.In the novel energy-dissipative shear wall,there is a vertical slit along the height of the structure and some metal dampers installed in the slit.Compared with shear walls without opennings,the deformation performance and the energy-dissipation capacity can be improved and the post-earthquake damage of wall pears can be reduced in slit shear walls.Four major tasks were performed in this thesis in order to study the seismic performance and design method of slit shear walls.(1)Elastic lateral stifiness and flexural capacity of the slit shear wall were derived through theoretical analyses,aiming at studying the structural performance.Based on the theorical analyses,several calculation examples were presented.The results show that stifiness and yield strength of metal dampers are key parameters affecting the structural performance of slit shear walls,which provides a theorical basis for further study.(2)OpenSees software was used to create a detailed numerical model for the slit shear wall.The accuracy of the developed model was verified through comparisons between analytical and experimental results of RC walls and metal dampers.The results show that the numerical model can accurately predict the hysteretic behavior of the wall piers and the metal dampers.(3)Based on the developed model,the hysteretic behavior of a shear wall without opennings and three slit shear walls under cycle loads was analyzed.Various results,such as failure mechanism,hysteretic curves,skeleton curves,load-carrying capacity,deformation performance and energy dissipation capacity,were obtained and then compared between these shear walls.The results show that when the metal dampers are designed appropriately,slit shear walls can obtain superior seismic performance,including enough stifiness and load-carrying capacity,good deformation performance as well as large energy-dissipation capacity.(4)The results of the above-mentioned theorical analyses and numerical simulation show that the stifiness and yield strength of metal dampers are key parameters when designing slit shear walls.Based on the results,parametric analyses were carried out,and the design coupling ratio(CRD)was proposed to indicate the difference of stifness and yield strength between metal dampers.The results of the parametric analyses show that the best design coupling ratio is 045～0.55.Slit shear walls can finally obtain expected superior performance when they are designed using a seismic behavior control method and choosing the best design coupling ratio.