Medium-Length Thin-Walled Cylinder under Wind Loading--Case Study

摘要

Depending on the geometry of a thin-walled cylindrical structure, three different stability failure modes under wind loading can be observed. In low cylinders, the radial compression at the windward meridian causes a buckling mode similar to cylinders under constant radial compression while very long cylinders display a failure mode characterized by buckling in the lower third of the structure at the side which faces away from the wind. Both of these failure modes have received a certain amount of interest by the research community, and design rules and proposals against both these failure modes exist. The failure of medium-height cylinders is characterized by a number of horizontal ripplelike buckles in an area around the upper half of the windward meridian. Comparatively little attention has been paid to this failure mode in the existing literature. A case study using a finite element model of a cylinder displaying this particular failure mode will be presented in this paper. The governing parameters for this rather unexpected behavior are identified and an explanation for the structural response is given. It is shown that the critical bifurcation mode is strongly dependent on prebuckling deformations. An imperfection sensitivity analysis for various imperfection types is also presented.