The Research On Seismic Responses And Vibration-reduced Control Of Prestressed Spherical Reticulated Mega-structure

The prestressed spherical reticulated mega-structure is a large-span lattice structure that can achieve structural balance by itself; in which the cables are laid out in the spherical reticulated mega-structure. This structure has the potential to have longer span compared to the traditional latticed shell structure, it is not only to satisfy the requirements of stability and saving iron and steel at the same time, but also can give full play to the material properties, in addition, the ultimate bearing capacity and economic efficiency are improved significantly in the structure. Therefore, the prestressed spherical reticulated mega-structure has good application prospect, and it has the extremely vital significance to analyze and research this structure.Based on the finite element theory, the seismic response behavior under seismic action and its seismic control are studied mainly by using software ANSYS. The main research work of this paper are as follows:At first, the basic theories about the anti-seismic are presented, including frequencies of vibration that are determined by solving dynamic equation via the subspace iteration method, Newmark method and the selection of the earthquake wave.As the span ratio is the important parameter of the structure,the optimal ranges analysis of prestress corresponding to the four cable arranging programs under different span ratios in common earthquake are carried out, as to provide reliable theoretical basis of seismic design and construction for the prestressed spherical reticulated mega-structure.At the same time, the effect of cross cable around arranging is most significant by comparing the optimal prestress value of kinds of cable arranging programs and prestress effect, thus the structure of cross cable around arranging is chosen as the typical structure for the earthquake response analysis in this paper.Detailed analysis of cross cable around arranging program of the prestressed spherical reticulated mega-structure is presented, considering the both condition of the main structure bearing the load by itself and cooperatively with substructures,the seismic responses under different seismic waves and that in common and severe earthquake are obtained, then the weaknesses of the structure subjected to earthquake action are found out.A novel damper, composite of Shape Memory Alloy (SMA) and Friction Materials, adopted to analyze the vibration controlling of the structure in this paper, for the purpose of reducing the structural response under seismic action and improving anti-seismic capacity and disaster prevention performance of the structure. Lastly,the vibration-reduced effect Composite Friction Damper had on the structure in serve earthquake, subjected to the three-dimensional El-Centro earthquake waves,is studyed in this paper.