Static And Dynamic Analysis Of Quasi-cylindrical Ribbed Arch Shell

By cutting the cylindrical surface into intersection planes,concrete quasi-cylindrical ribbed arch reticular shells are formed.In this paper,the prismatic arch ribbed reticular shells and quasi-cylindrical folded reticular reticular shell structures are taken as research objects.The finite element analysis method is used to calculate the deformation and internal forces of the structure under point-support conditions.The effects of factors such as the sagittal ratio,ridge line,main arch,rib,side beam stiffness,and roof thickness are used to parameterize the static and dynamic characteristics.Analysis,in order to understand the structure of the internal force and stiffness distribution characteristics,vibration mode and frequency,to provide reference for engineering applications.The analysis of the static performance and dynamic characteristics of the prismatic arched dense-ribbed reticulated shell structure shows that the internal force and deformation of the structure are not linearly related to the vector-to-span ratio,and the structure can be viewed as a one-way force-transmitting structure composed of broken line arches.The maximum deflection occurs on the ribbed flat plate,and the structural rigidity is large;the internal force distribution of the structure can be clearly partitioned;the support arch is the main force transmission structure;the internal force of the ridge line and the horizontal rib is small;when the roof is fixed at multiple points,the end The spacer is small,the side beam is a double eccentric force member;the end spacer makes the force of the structure be between the arch shell and the shell shell,so setting the end spacer can significantly increase the vertical stiffness of the structure and change the third-order The vibration mode improves the seismic resistance of the structure;when the ratio of the span to span does not exceed 1/6,the fundamental frequency increases with the increase of the cross-span ratio;the stiffness of the ridge has little influence on the overall stiffness and bearing capacity of the structure;the main arch can be regarded as dense The elastic support of the rib plate,improve the rigidity of the main arch is beneficial to reduce the internal force of the remaining components of the structure and enhance the overall rigidity of the structure;simultaneously improving the stiffness of the two-direction ribs will greatly increase the overall stiffness of the structure and affect the self-supporting capacity of the ribs.Changing the cross-sectional height of the side beam does not affect the overall stiffness of the structure.The analysis of the static performance and dynamic characteristics of the quasi-cylindrical bi-lamellar reticulated shell shows that: based on the finite element calculation results,the structure can be regarded as a bidirectional force-transmittingstructure composed of broken line arches.The maximum deflection occurs on the ribbed plate.The structural rigidity is large;the internal force distribution of the structure can be clearly partitioned;the arch support belt,the cross-middle arch belt,and the ridge line are the main force transmission structures;the internal force of the horizontal rib is small;when the roof is fixed at multiple points,the horizontal and vertical ends are separated.Less effective,edge beam is a double eccentric force member.Lateral folding,excessively large span ratio will increase the arch span of the ribbed slab,leading to increased structural deflection.With the same other parameters,the deflection in the longitudinal direction will reduce the structural deflection by more than half and the overall stiffness of the structure.A lot of improvements have been made;the longitudinal separation has almost no effect on the mode shape and frequency of the structure,and the fundamental frequency decreases with the increase of the transversal span ratio.The vertical folding of the structure effectively increases the overall stiffness of the structure,and the fundamental frequency varies.With the increase of the vertical vector height,the ridge line is used as the vibration node line,but the ridge line stiffness has little effect on the overall stiffness of the structure,and has little effect on the internal force of the structure.Based on the principle of internal force distribution according to the stiffness,it is beneficial to increase the stiffness of the main arch.Reduce the internal forces of most of the rest of the structure and increase the overall stiffness of the structure.Due to configuration reasons,increasing the stiffness of the two-way ribs simultaneously can increase the overall stiffness of the structure to a certain extent,affect the self-supporting capacity of the ribs,and reduce the internal forces of the main arch and ridge;the increase in the stiffness of the side beams has no effect on the overall stiffness of the structure.There is also no significant effect on the improvement of structural internal forces.