Compression Tests of Longitudinally Stiffened Plates Undergoing Distortional Buckling

摘要

This paper describes a series of compression tests performed on longitudinally stiffened platesfabricated from mild steel plates of thickness 4.0 mm with nominal yield stress of 240MPa. Thestiffened plates with a range of rigidities of longitudinal stiffeners were tested to failure. Theultimate strength and performance of the longitudinally stiffened plate in compression undergoingdistortional buckling or interaction between local and distortional buckling were investigatedexperimentally and theoretically. The compression tests indicated that the critical buckling modewas dependent mainly on the rigidity of the longitudinal stiffeners and the width-thickness ratio ofsub-panels. A noticeable interaction between local and distortional buckling was also observed forsome stiffened plates. A significant post-buckling strength reserve was shown for those sectionswith distortional buckling or with interaction between local and distortional buckling. A limitingstrength curve for distortional buckling for stiffened plates was studied. Simple design strengthformulae in the Direct Strength Method have been proposed to account for the interaction betweenlocal and distortional buckling of stiffened plates. The strength curves proposed were comparedwith the test results. The adequacy of the strength curve was confirmed. A set of conclusions wasdrawn from the experimental studies as to the buckling behaviour of stiffened plates.