Stability of large-span single-layer cylindrical reticulated shells supported along four edges

Abstract:

To widen the span range available for single-layer cylindrical reticulated shells,parameter analyses based upon nonlinear complete-process analysis were carried out.More than 400 examples of single-layer cylindrical reticular shells with width of 20 meters and supported along the four edges were calculated by finite element method software ANSYS and self-developed pre-and post-processing programs.The buckling modes,critical loads,plastic development levels were collected to investigate the effect of length-width ratio,rise-span ratio,initial geometric imperfection,and unsymmetrical distribution of loads.The results show that single-layer cylindrical reticular shells supported along the edges are still characterized by bending action,and the central regions of shell structure are the most sensitive areas.When the length-width ratio becomes larger,it is necessary to add the stiffening ribs to enhance the rigidity of shells,and the spacing of which should be set to make the length-width ratio be 1.0.The cylindrical reticulated shells are concluded to be sensitive to initial geometric imperfection,when the initial imperfection value reaches 1 /300 of the width,the critical loads of reticulated shell will be reduced by 30%.And when the loads are unsymmetrical distributed with p/g=1.0,the critical loads will be 86%-94% of those under symmetrical loading distribution.