Analysis Of The Interaction Between Core Tube And Frame In Twisting-shaped Building Structure

The twisting-shaped building is the product of the rapid development of social economy and has extremely high aesthetic value.However,the building structures should be designed as simple and regular as possible,so twisting-shaped buildings put forward higher requirements for structural design.In order to study the overall structural performance characteristics of the twisting-shaped frame with concrete tube,theoretical study on the simplified mechanical model of the twisting-shaped structure and comparative analysis on 20-story twisting-shaped and non-twisting-shaped structure models were carried out.The main work of the thesis is as follows:1)The calculation formula of floor torque is derived by decomposing the force of the simplified model of twisting-shaped structure.A simplified structure mechanical model of single-story twisting-shaped structure was established by using the finite element analysis software ETABS.The distribution of floor torque was analysied.The influence of the tube wall and beam components on the torque distribution on the floor was considered.The research results show that the twisting-shaped structure generates torque on the floor due to the inclination of the columns.The torque is transformed into the shear force of the columns along the torsion tangent direction,the torque of the column itself,and the shear force on the horizontal section of the core tube.The torque distribution in floor slabs is greatly influenced by the elastic floor assumption,somewhat influenced by beam members.The torque distribution in the floor under rigid floor assumption is the closest to the theoretical value.2)The analyzation on the dynamic characteristics,structural lateral displacement and member internal force of the twisting-shaped structure and the non-twisting-shaped structures shows that the twisting behavior of twisting-shaped structure is worse than that of non-twisting-shaped structure,the lateral displacement and the member internal force of twisting-shaped structure are greater than that of non-twisting-shaped structure.Under the same vertical load,the internal forces and deformation of the main components in twisting-shaped structure are much greater than that in non-twisting-shaped structure,and the internal forces distribution in shear walls and coupling beams of the two different structure types are also completely different.3)The elasto-plastic time history analysis of non-twisting-shaped and twisting-shaped structures under rare earthquakes has been carried out.The research shows that under the same seismic wave action,the inter-story displacement angle and the numerical sum of the floor shear force,there is no obvious difference in the shape of the curves.After the outer frame of the structure is twisted,there is no obvious change in the seismic performance of the structure.4)Analysis of influence factors on twisting-shaped structure shows that the most effective way to control the lateral displacement of the structure is to expand the proportion of the core tube,followed by changing the connection method of the two ends of the floor beams,and increasing the thickness of the outer wall of the core tube is the least effective.Therefore,it is suggested that increasing the proportion of the core tube to control the side shift of the structure.