Axial And Hysteretic Behavior Of Rectangular Multi-partition Steel-concrete Composite Short-leg Shear Walls

Reinforced Concrete Short-legged Shear Walls(RCSSW) have been used widely in high-rise buildings in China, with their distinctive advantages such as various cross-sectional shapes, flexible positioning, and beautiful combination of both load bearing and space planning requirements. In order to improve RCSSW bearing capacity and earthquake resistance performance, a new type of shear wall is proposed, which is composed of multi-partition hollow steel sections filled with concrete and named “Short-legged Multi-partition Steel-concrete Composite Shear Wall(SMSCSW)”.The new SMSCSW can achieve a high bearing capacity, good energy absorption and deformation ability through the composite action between multi-partition steel tubes and in-filled concrete. Moreover the multi-partition steel tubes can also be used as load bearing members and concrete forms in the process of construction, which provides great convenience to the site work. Up till to now, there is little research on SMSCSW, this dissertation focuses on rectangular section multi-partition composite shear walls. The main works are listed as follows:(1) The finite element software ABAQUS is applied to analyze the axial compression behavior of SMSCSW. The geometric and material non-linear behavior, and initial geometric deformation are consiederd in the analysis. The existing experimental results are used to validate the accuracy of finite element analysis results. And then the influence of breadth-to-width ratio of section, the width-to-thickness ratio of the steel plate and material strength on the axial compression behavior of structural element is analyzed. The analytical results showed that the multi-partition hollow steel tube confined the inside concrete well, thus the bearing capacity and ductility of SMSCSW increases obviously comparing with the sumation of strength from steel tube and core concrete. At last, a simplified method is proposed to calculate the axially compressive bearing capacity of SMSCSW.(2) Two SMSCSWs with rectangular cross-section were fabricated and tested. These specimens were subjected to axial compression combined with reversed cyclic lateral load. The main parameter varied in the tests was axial compression ratio. The deformation development process, stress development process of key point and failure mode of specimens are analyzed. The results indicate that the SMSCSWs possesses high strength, good ductility and energy dissipation ability. The axial compression ratio is an important parameter, which inlfuence the hysteretic behavior of SMSCSW. With the increase of the axial compression ratio, the elastic stiffness of section increases, while the bearing capacity decreases slightly and the ductility decreases obviously. The energy dissipation capacity is improved with the increase of axial compression ratio.(3) The finite element software ABAQUS is used to develop the model to analyze the hysteretic behavior of SMSCSW. The accuracy of finite element results is validated by comparing with the experimental results. Then the typical SMSCSW is analyzed to study its working mechanism more clearly. At last, the influence of shear span ratio, axial compression ratio, the width-to-thickness ratio of steel plate, and etc. on the hysteretic behavior of SMSCSW is discussed.