Nonlinear Buckling Of Parabolic Single-layer Cylindrical Reticulated Shells

single-layer cylindrical reticulated shell is a common structural form of large span roof structures, the difference in the form of the arch alignment would result in the difference in the mechanical behavior of the structure. In practical engineering, the single-layer cylindrical reticulated shell is widely used for its graceful shape and easily-construction, therefore, some other more reasonable single-layer cylindrical reticulated shells of different arch line with better mechanical behavior are ignored-such as the parabolic single-layer cylindrical reticulated shell and the inverted catenary single-layer cylindrical reticulated shell.Based on the present situation, the static stability of the parabolic single-layer cylindrical reticulated shell is analyzed and studied in this paper.(1)For the parabolic single-layer cylindrical reticulated shells with different forms of grid layout, their ultimate bearing capacity are compared to determine the most reasonable form of grid.(2) with the reasonable form of grid layout, the static stability of the parabolic single-layer cylindrical reticulated shell is compared with the single-layer cylindrical reticulated shell and the inverted catenary single-layer cylindrical reticulated shell.(3) A large scale parameter analysis is carried out on the parabolic cylindrical reticulated shell, the parameters include: length-span ratio, raise-span ratio, member section dimension, asymmetric load distribution, initial geometric imperfection and settlement of support, etc. Then, an optimized design for the parabolic single-layer cylindrical reticulated shell is conducted. Unlike previous optimization approaches in which truss is widely used, the optimized design in this study is focused on the layout of the grids, including the oblique rod intersection angle and the grid space layout.Research shows that: for the parabolic single-layer cylindrical reticulated shell, the three-dimensional grid layout has the best stability performance, compared with the traditional cylindrical reticulated shell, both the stiffness and the ultimate load of the parabolic single-layer reticulated cylindrical shell and the inverted catenary single-layer cylindrical reticulated shell greatly enhance. Raise-span ratio and length-span ratio influence the parabolic single-layer cylindrical reticulated shell significantly and have a good regularity; the ultimate load of the parabolic single-layer reticulated cylindrical shell and section equivalent stiffness are in a linear relationship; the reticulated shell are proved to be sensitive to initial geometric imperfection and it should be controlled; the reticulated shell is not sensitive to the asymmetric load; The intersection angle of the oblique rods along the direction of the arch influence the ultimate load of the parabolic single-layer reticulated cylindrical shell significantly. There exists a optimal oblique rod intersection angle that makes the static stability of reticulated shell the best. This optimal angle is about 50°. When the grid space layout is arranged according to the geometric series and the value of the ratio α is between 0.85 to 0.95, the shell has the best static stability.