Geometric Imperfections in Plated Structures Subject to Interaction between Buckling Modes

摘要

An analytical technique is described for expanding a measured geometric imperfection surface in the buckling modes of a structure. The surface is expanded longitudinally as well as transversely. In the transverse expansion, the constituent plates are treated as a plate assembly so that the imperfections of the individual plates can be interrelated. The technique is applied to a channel section which buckles interactively in an overall flexural mode in the plane of symmetry and a primary local buckling mode. The imperfection components of these modes are determined, as are the components of the secondary local buckling modes which may be triggered as a result of the interaction between the overall and local modes. The imperfection components are determined approximately from imperfection measurements taken at six points in each cross-section along the length of the column. The application of the technique to other cross-section types is mentioned.