Static And Dynamic Performance Analysis Of Four-span And Long-span Concrete Ribbed Frustum

The concrete reticulated reticulated shell structure is a kind of new type of space structure based on the multi-ribbed plate and the flap shell.It is composed of a multi-ribbed flat plate at the ridge line(valley),and its transmission path is clear and in various forms Compared with the traditional reticulated shell structure,the new type of reticulated reticulated shell can not only reduce the difficulty of the construction of the template of the smooth curved reticulated shell,but also can avoid the phenomenon that the sound is too concentrated by increasing the diffuse reflection,which can meet the concept of modern green energy saving building.Different structures have different forms of stress.This article mainly talks about folded-plate quasi-shallow reticulated shell and folded-plated ribbed shell.Finite element model that applied space beam element and shell element to in four point boundary conditions was established,this paper discussed the influence of the rise to span ratio,ridge line stiffness,ribbed beam,and side beam stiffness factor to the structure static behavior and dynamic characteristics.Finally,the range of geometric dimensions of the main components of the structure is given.The results of folded-plate quasi-shallow reticulated shell show that the ribbed slab which distribution of bending moment is similar to using for floor has arch effect in the roof;the distribution of the structural spectrum characterized intensive and jump,and low-order vibration type taken the ridge section as line edge vibration.The top chord on the edge truss is main member for transferring force and truss plane stiffness has great influence on the vibration mode;Increasing the ribbed beam stiffness can significantly improve the stiffness of structure,the low height-to-span will increase axial force of structure,The ridge stiffness has little influence on static behavior of structure,so the height-to-span of structure should not be less than 1/6,the ratio of sectional height to span of the ridge is suggested to be 1/50~1/30,the ribbed beam section height is determined by the 1/60~1/35 of structure span,The top chord on edge truss section height can be the same as that of the ridge section.The results of folded-plated ribbed shell show that ridge is very important to Transfer internal force,the distribution of the structural spectrum characterized intensive and jump,the increase of height-to-span ratio to reduce the structural internal force,The strengthen of the rigidity of ribbed beam plays a certain role as for improving the structure stiffness,Improving the rigidity of side beam will significantly reduce the maximal deflection of structure;The height-to-span is suggested to be 1/6~1/4.the ridge section altitude is 1/40~1/25 of the span.the proposed ribbed beam section height can be determined according to the roof span of 1/45~1/30;the ratio of sectional height to span of the side beam is suggested to be 1/30~1/20.Finally,the study pointed out that the problems which need to be resolve urgently in the next study.