Synergistic Effect Analysis And Connection Analysis Of The Low-carbon Wind Tunnel Building Of Tianjin University

With the rapid development of national economy and the continuous advancement of technology, people for the diverse needs of structure is also growing. A variety of new structural forms and spatial structure of the system get attention and development. Different types of structure is always considered separately in the traditional design of building structures. For example, the main structure and large-span roof structures are analyzed separately. This method can not reflect the contribution of large-span roof structure's stiffness to the main structure and its impact on the main structure under various loads. The amplification of building envelope due to the finite stiffness of the main structure and elastic support at the conjunction are not considered, either. There is a certain security risks in this way.Based on the low-carbon wind tunnel building of Tianjin University, this paper analyzed the beam string structure and the body frame structure separately, and studied the characteristics of the members' internal force and the structures' deformation. On the base of the isolated modeling analysis, assembled modeling analysis of the lowcarbon wind tunnel building of Tianjin University was done. The results between the isolated model and the assembled model was compared. The reason for the difference of stress and displacements was investigated. The importance to consider the synergistic effect was described and the necessity of assembled model analysis was evaluated.For the lack of the mixed welded and bolted connection, this paper proposed a new connection style of the concret-filled square steel tubular column and steel beam based on the diaphragm-through connection. That is bottom flange bolted and top flange welded diaphragm-through connection. In order to study the seismic performance of the connection, finite element model was founded by Abaqus. Large geometric deformation, material nonlinearity and contact condition were considered and the bolts number that connect the bottom diaphragm and the bottom flange was set as a parameter. Through finite element analysis, the stress distribution and connection seismic resistance capacity were obtained.The results show that the failure of the connection is due to the bukling of the flange near to the top diaphragm. The bukling site is near the heat affected zone which avoid the key parts of the column root. The plastic hinge appears on the beam, which reflects the seismic requirements of the "strong column and weak beam, strong connection and weak member". With the increase of the bolts number, the initial stiffness of the connection will increase. At the same time, the yield and ultimate bearing capacity of the connection will improve. However, the difference between the stiffness degradation rate is little. The shape of the hysteresis curve is full like spindle, which indicates that the seismic behavior of the connection is good. The ductility coefficient of the connection was 2.746 and accumulative equivalent damping coefficient researched 0.388. The ductility and the seismic behavior of the connection is good.