Parametric Design And Seismic Response Analysis Of Hybrid Saddle Reticulated Shell With Circular Horizontal Projection

With the rising popularity of large span and large space buildings, people have not used the traditional pure topology in the form of reticulated shell directly, and they tend to combine different structure forms, with their respective advantages to meet the architectural aesthetics, reasonable and economic new structure form, then the hybrid saddle reticulated shell arises at the historic moment. It can not only bring comfort to people but also can increase the span of the structure, make grid cell distribution uniform, make force reasonable, bring higher economic benefits. Based on the combination laws of hybrid reticulated shell and better form of optimized structure, this paper developed macro program of 12 kinds of hybrid saddle reticulated shell with single-layer circular horizontal projection by using APDL (ANSYS Parametric Design Language) Parametric Design Language, and analyzed their shape optimization, general characteristics under static and dynamic analysis, and finally obtained some important conclusions.(1) According to the saddle surface equation, z=2f/S2(x2-y2), where f means vector height, S means span, this paper developed macro program of 12 kinds of hybrid saddle reticulated shell with circular horizontal projection by the five kinds of saddle shell(ribbed, Lamellae, Kiewitt, Schwedler and three-dimensional saddle reticulated shell) mutual combination. The parametric design of the reticulated shell structure could be realized fast, conveniently and efficiently after inputting the vector height, span, ring to symmetric regional copies number, radial node ring number, and the upper structure of radial ring, which laid a solid foundation for the performance analysis, selection optimization, popularization and application for this kind reticulated shell.(2) Taking gravity into consideration, applying static load to 12 kinds of hybrid saddle reticulated shell structure, and by comparing the maximal displacement, internal force and the maximum horizontal counteracting force under different parameters, this paper induced the suitable span and vector height of the respective 12 kinds of structure models, which provided basis not only for theoretical in engineering design but also for dynamic analysis of shell structures.(3) Saddle Reticulated Shell was studied with objective function of minimum steel consumption and shape optimization design variables Kn(ring to symmetric regional copies number), Nx(radial node ring number), Ns(the upper structure of radial ring). The optimal combination of Kn, Nx, Ns, when the total steel consumption was minimum, provided reference for the applications of hybrid type saddle shell macro micro geometry relationship. Based on the cable arch orthogonal characteristics of the saddle reticulated shell, this paper deduced the formulas between the bar length and parameters of three kinds of hybrid saddle reticulated shell. In the progress of structural design, with the given span, Kn and Ns, the length of the bar and vector height could be ensured by using the formulas in engineering, in addition it could reduce the cost and cycle of the design, improving the efficiency.(4) Seismic response analyses were studied of the two types selected in 12 kind hybrid saddle reticulated shell structure which have a better static performance, analyzing the natural vibration characteristic and the influence of structure parameters on frequency. Vibration characteristics under the action of one dimensional earthquake, two-dimensional and three-dimensional earthquake were analyzed by using time-history analysis method, and node displacement, internal force time history curve. Through analyzing the influence on the displacement and internal force of structure caused by varying parameters of span, vector height, ring to symmetric regional copies number and radial node ring number, it obtained the seismic response law of the hybrid saddle reticulated shell and gave some reasonable suggestions.Finally, analyses of the relevant conclusions are summarized and the prospects of the hybrid saddle reticulated shell structure are put forward.