Study On Static,Aseismic And Wind-Resistant Behaviors Of Beam String Structures

The Beam String Structures(BSS), using bar connecting arches and cables, is a new type of long-span structures. In recent years, BSS is becoming one of the focus for study in the field of space structures because of its successful applications in many important long-span buildings. Based on the previous researches, this thesis reinvestigated some static properties of BSS, and the aseismic and wind-resistant behaviors of BSS were studied with emphasis.Based on the local analysis method, the distribution and the sampling rules of initial pre-stress was discussed, and it was revealed definitely that BSS is sensitive to pre-stress which has limited effects on improving the static properties. There are also many disagreements with the influence of rise-span ratio, sag-span ratio and the pre-stress of string on the static properties of single BSS, which were reviewed more comprehensive with numerical and theoretic analysis in this paper.The static behaviors of dual-direction BSS were researched systemically in this paper. In comparison with single-direction BSS, some limitations such as the non-uniform distribution of stiffness and insufficient use of the lower cable-strut structure were presented, and the calculation and analysis show that non-guarantees of thickness of peripheral single BSS is the main reason. Accordingly, it was suggested that the structures with fewer single BSS and cables in folded pattern should be given priority to select when the span was given.The aseismic behaviors of BSS were studied systemically. The analysis on dynamic property of BSS show that the vertical vibration modes is primary, and the geometrical stiffness has little influence on the natural vibration characteristics. The response spectrum method was used to analyze the seismic responses of single-direction and dual-direction BSS, and the results were summarized. Furthermore, the thesis adopted code simplified method and time history analysis to calculate the response of BSS under vertical seismic action and compared the results, so that the applicability of three methods were investigated respectively and it was suggested that code simplified method is not suitable. The effects of the relevant structure parameters on aseismic behaviors of BSS were discussed briefly in the end.The wind-resistant behaviors of single-direction BSS and dual-direction BSS were studied in detial. This paper wrote out the programs on the frequency domain method and on the simulation program for artificial wind, which were employed to calculate the wind-induced dynamic responses of single-direction BSS respectively. Based on the comparison of the computed results using frequency domain analysis and time domain analysis, the effectiveness of frequency domain method was proved. Wind-induced dynamic behaviors of single-direction BSS relating with some important structuralparameters, including rise-span ratio, span and roof load, were also discussed in detail. At last, wind-induced dynamic behaviors of dual-direction BSS were analyzed based on frequency domain method, and according to the conclusions, the main principles and suggestions on wind-resistant analysis and design of BSS were put forward.