Study Of Vibration Reduction Of Cylindrical Reticulated Mega-structure With Viscous Dampers

The cylindrical reticulated mega-structure mainly composed of main structures and substructures is a new space grid structure pattern and an ideal form of grid structure because of clear mechanical hierarchy, fewer types of structural members and facilitation of construction. With the continuous increasing requirement to space, the structural patterns have been developed to super high rise and large span spatial. At present, the theoretical research and engineering applications of vibration control of structures focus on high-rise building and the research to large span spatial structures is still rare. Viscous damper related with the stiffness and velocity is made based on the principle that fluid flows over the orifice would produce the viscous drag. The viscous damper device has good performance in vibration control of structures for simplicity in construction, economical materials, less effect to environment, facilitation of construction, effective shock absorption and less violation to original structures. Based on the above background, this paper mainly carried on the research of vibration control of cylindrical reticulated mega-structure using viscous damper device. A typical cylindrical latticed-intersected-three-dimensional-beam-system reticulated mega-structure was selected to research the efficiency of vibration control of viscous damper device to structures under frequent and rare earthquake. The main research contents of this paper include:Firstly, the natural vibration characteristics of the structure were analyzed, which concluded that the fundamental frequency is lower as well as the global stiffness especially in the longitudinal direction and it is necessary to control the vibration of the structures.Secondly, under frequent earthquake, the time-history method based on numerical software, ANSYS, was adopted to analyze of the performance of vibration control of viscous damper device to structures excited by seismic wave adjusted according to the specification in three dimensions at the same time with varied damper distributions and damping parameters using the indicators of the peak values of displacement and acceleration of the nodes in the structure. With the identify the optimal damper distribution and damping parameters, the response amplitude changes of the nodes and historical curve of the nodes where the peak values of displacement and acceleration appear without vibration control were explored with the excitation of two different seismic waves. Based on the determination of the vibration control system with the input of seismic waves in three dimensions, the response characteristics of the structures and the performance of dampers were analyzed with the input of the seismic wave in each of the three directions.Finally, based on the determination of the vibration control system under frequent earthquake, the results of vibration control are explored with the different excitation of rare seismic wave in three dimensions at the same time using the nodes displacement and acceleration, member internal forces and the mechanical characteristics of viscous damper.The conclusions of this paper has are helpful to the design of viscous dampers to reduce the vibration of Cylindrical Reticulated Mega-structure.