Axial-Weld Land Buckling in Compression-Loaded Orthogrid Cylinders

摘要

Large stiffened cylinders used in launch vehicles, such as the space shuttle external tank, are manufactured bynwelding curved panels into complete barrels. The effects of the axial-weld lands between the panels on the bucklingnstrength of unpressurized cylinders are studied, along with the interaction between the acreage stiffenernarrangement and the weld land geometry. The relatively thick, unstiffened axial-weld lands are shown tonsignificantly reduce the buckling load when the cylinder is loaded in uniform axial compression, and a relationshipnbetween the reduction in buckling load and the orthogrid design is shown. Reducing the width of the weld lands isnshown to be the most effective means of minimizing the reduction in buckling strength, and thicker weld lands arenshown to not always increase their buckling resistance. Detailedmodels with individual stiffenersmodeled as beamsnare used to show that the weld land buckling phenomenon is very sensitive to the specific location and geometry ofnstiffeners near the axial-weld lands. It is also shown that the buckling strength can be significantly improved bynensuring that the distance between the weld land and the adjacent longitudinal stiffener is minimized.