Pregnant Beam-Column Element For Global, Local and Intercation Buckling

Design methods for thin-walled structures usually guards against two types of buckling;overall (member) buckling and local (plate) buckling. With increasing use of cold-formed sections with slender plate components and low torsional rigidity, the interaction between global and local modes should not be overlooked. Finite element analysis using plate or shell elements or finite strip analysis can be employed for this purpose. Such an analysis is more feasible for a single member or a small subassembly rather than a full-scale structure. A compact technique for bifurcation analysis of thin-walled structures is presented in this paper. The technique is capable of predicting global, local and interactive buckling without the need for discretisation of the cross-section. For this reason the method lend itself for preliminary analysis of practical structures. In this approach, a pregnant beam-column element is developed whereby the global modes of a standard beam-column element are impregnated by the local modes. The concept of amplitude modulation is then introduced to account for the interaction between global and local modes

Keywords:

Global , local , interactive buckling , thin-walled structures