Static And Dynamic Performance Analysis Of A Quasi-spherical Ribbed Folding Net Shell Roof

Based on the mechanical properities of the ribbed floor, thin shell structure and folded plate structure, a new type of large span concrete space grid structure- ribbed type folded plate net shell roof structure was proposed. The structure in the valley line or in the ridge line was composed by multiple pieces of ribbed flat intersection according to certain rules, in order to meet the needs of the modern building roof of the modelling, it can can make corresponding cutting on space geometry, structure form is varied, and get colorful roof structure.This article uses the FEM to carry out the fitting spherical ribbed folded plate net shell static performance and dynamic performance of the research, the results show that:State of structure is similar to the net shell structure stress state; constraints between folded plate deformation, greatly improve the in-plane stiffness. Depending on the various factors on the vertical stiffness and the influence of the stress components, to be spherical triangle grid ribbed folded plate net shell roof, rise-span ratio values should not be less than 1/3 ~ 1/8. Deputy ridge line beam section height should take 1/50 of the span; Beam section height should take 1/5 ~ 1/4 of the beam span; As to spherical triangle grid ribbed folded plate net shell roof, recommended ridge line edge beam dividing the grid size is about 1.2 m; Su ggest appropriate increase ridge line and edge beam stiffness.Natural frequencies of the structure has the characteristics of the distribution, type and frequency of vibration curve has obvious jump the steps, the same on the steps of the corresponding vibration mode similar frequency; The main structure of low-order modal vertical vibration in the folded plate near the border.The floor has larger stiffness than the supporting parts. The deformation of the overall structure is bigger than pure roof, fundamental frequency smaller than pure roof; Edge beam tension and side thrust is more obvious; Suggest increasing the rise-span ratio, make the structure more reasonable and more superior deformation smaller; The beam stiffness, suggest increase prestress, and improve the reinforcement ratio to increase resistance of beam tension; Suggest increase the column stiffness, otherwise the supporting part of upper structure is just enough structure is soft enough not conducive to structure seismic; Whole model of the fundamental frequency is not sensitive to the change of the rise-span ratio, and sensitive to the change of columns stiffness.Theoretical analysis proved that this new type of roof structure has good integrity, large carrying capacity and stiffness, more safety. The structure is a good choice for the multi-storey public buildings and large span concrete in civil building structure...