الفهرس | Only 14 pages are availabe for public view |
Abstract The theoretical investigation described in this thesis deals with the behaviour of truss members made of cold-formed steel sections.the relative thickness of these sections is the source of many design problems specially in compression members.one of these serious problems is the interaction between plate buckling of the section components and the overall buckling of the member. The local buckling is a stable mode in which the plate can carry loads above that of its critical load. However, the overall buckling mode is a neutral one in which the member retains its load carrying capacity when the critical load is reached but will not be able to carry loads greater than the critical value. Individually, the two principal modes are stable in the sense that there is no loss in load carrying capacity after bucklong, whereas an interaction brtween them could be very imperfection sensitive with peak elastic load below the critical loads in either the individual modes of buckling. The work reported in this thesis is concerned with an analytical investigation of the non-linear interactive behaviour of cold-formed steal sections up collapse load,taking into account many variables such as cross section properties, and conditions and the effect of both local and overall initial imperfections.the theoretical solution is essentially an elastic analysis based on a step-by-step scheme.the local bucking effect was a varying effective plate stiffness concept. |