Buckling Collapse Testing of Friction Stir Welded Aluminum Stiffened Plate Structures

摘要

The objectives of this study were to develop a mechanical buckling collapse test database for 5000's and 6000's series aluminum stiffened plate structures fabricated by friction stir welding and to compare these structures with similar aluminum plate panels fabricated by fusion welding in terms of weld-induced initial imperfections and ultimate compressive strength performance. The trends or benefits found to be associated with the fusion welding and friction stir welding procedures are discussed. The following is a summary of these discussions: (1) It is found that the yield and ultimate tensile strengths of friction stir butt-welded aluminum alloys are equivalent or even better than that of fusion-welded aluminum alloys; (2) The initial imperfections induced by friction stir welding tend to be smaller than those induced by fusion welding. Thus, the benefits of the friction stir welding procedure in this respect are clear; (3) The ultimate strength performance is found to be 10-20% greater in the friction stir-welded aluminum structures than it is in the fusion-welded aluminum structures. This implies that the friction stir welding procedure is certainly superior to the fusion welding procedure in terms of ultimate compressive strength performance, as long as delamination is prevented; (4) All of the friction stir-welded test structures however showed delamination in the welded region after or even before the ultimate strength had been reached. This indicates that the fusion welding procedure is superior to the friction stir welding procedure in terms of compressive strength performance in the welded region; and (5) It is reconfirmed that nonlinear finite element method computations depend significantly on the structural modeling techniques applied.