Seismic Performance Study On High-rise Twisted Diagrid Tube Structural System

The emergence of high-rise buildings is a need for the development of human society.Twisted high-rise buildings as a new type of architectural,its extraordinary architectural design style requires structural engineers to break through the conventions ideas and explore appropriate structural systems.The high-rise twisted diagrid tube structure is the combination of diagrid tube structure and twisted high-rise building.Due to its beautiful architectural shape,spatial strength evenly,and superior torsional performance,it has attracted the attention of many scholars and engineering practitioners in recent years.However,as an emerging structural system,there are very few theoretical studies,the mechanism of stress is not yet clear,and there is no systematic theoretical support for engineering applications.The purpose of this study is to find out the effects of distortion degree on the stress and seismic ductility of the twisted diagrid tube structure,and then provide theoretical support for practical engineering applications.Firstly,this dissertation starts from the concept of structural system,introduces the twisted diagrid structure system after systematically discussing the diagrid tube structure system.Subsequently,the structural characteristics are introduced in terms of its structure arrangement,rotation angle,and space modeling,etc.Diagrid tube structures,in order to achieve the distorted body shape,can be rationed sequentially through the floor or the vertical members are regularly tilted.The addition of diagonal braces improves the lateral stiffness of the structure,and at the same time enriches the load transfer mode,which is a great help to improve the structure's ability to resist continuous collapse.The structure was then subjected to elastic analysis using a response spectrum method.The results of modal analysis show that proper torsion reduces the natural vibration period and maximum displacement of the apex,indicating that the stiffness of the structure is increased,and the total rotation angle is preferably 90 degrees.At the same time,the twisting behavior also causes the transmission of the vertical load to be biased toward the side column,and the force of the diagonal bracing also increases as the degree of distortion increases.Finally,the static elastoplastic analysis uses the Pushover analysis method based on the performance seismic design concept.The ductility of the structure was evaluated from three aspects: Pushover curve,interlayer displacement angle and plastic hinge.The results show that the addition of the distortion factor reduces the plastic deformation ability of the structure.The development of the plastic hinge of the component also indicates that the plastic development after the distortion is not as good as that of the non-twisted structure,and the plastic damage of the bracing is more serious after the distortion.