| Based on the research status of super-span dome structural system,this paper puts forward the structure of lotus-shaped and bamboo-shaped single-layer spherical reticulated shells,which the principal structural system are composed with radial main arches and oblique arches.Through lectotype analysis,optimal structure with novel appearance and well-behaved property is presented.Based on the preferred shell scheme,an innovative lotus-shaped reticulated mega-structure adopted to super-span dome is proposed.The research work carried out in this paper can be listed as follows:Model selection analysis is launched in the first place.Lotus-shaped and bamboo-shaped single-layer spherical reticulated shells are proposed first.With parameter changing such as the number and location of inner ring bar arranged,radial straight arch arrangement and circumferential divisions for lotus-shaped single-layer spherical reticulated shells,and central connected or disconnected radial obliqued arch,circumferential strengthen member distribution,radial and circumferential divisions for bamboo-shaped single-layer spherical reticulated shells,the variations of peak internal force,deflection,stability capacity and steel consumption are compared.Innovative and aesthetic structural forms with different inclined arch distribution,which the mechanical properties and steel consumptions are comparatively equal to that of traditional ribbed reticulated shell,are put forward.Constructed within optimal scheme,geometric modeling method and analysis program are composed for lotus-shaped reticulated mega-structure.Geometric controlling parameters of the structure are obtained via composition analysis.By using Rhinoceros,3D-forming method is summarized,within which the modeling analysis process can be flowed.Pre-processing program for geometric model importing from Rhinoceros to ANSYS and fully stressed optimization program for structural optimum design are also compiled.Taking into consideration of structure weight,additional dead load,live load,wind load and thermal action,static analyses of the structure are carried out.Structural internal force,maximum displacement and related distribution characteristics of lotus-shaped reticulated mega-structure among different load combinations are studied so as to evaluate static behaviors.Besides,Regularity distribution along the axis of internal force on each part of spatial truss members are ploted.The chaging trend of regularity with the variation of rise-to-span ratio is also obtained.Stability analyses considersing geometric and material nonlinearity are conducted to investigate structural elastic and elasto-plastic stability capacity.Firstly,buckling analysis is proposed to obtain buckling modes and eigenvalues of the structure.The influence factor such as initial geometry defect is also taken in to account to evaluate stability performance and influence regularity.The static and stablity behaviors of eight parameters varied such as circumferential division number,span,inclined angle,rise-to-span ratio,height and width of the spatial truss,fully-stressed ratio and supporting conditions are studied primarily,in which approximately one hundred cases of lotus-shaped reticulated mega-structure elasto-plastic whole-course analyses are carried out.Within large-scale parametrical analysis,the influence of changing parameters on internal force,vertical deflection,support reaction force,stability capacity and steel consumption are investigated and reasonable range for well-behaved structure are also summarized.Futhermore,the research provides reference for futher theorical study and somehow promotes pratical engineering application. |
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