Requirements for auxiliary stiffeners attached to panels under combined compression and shear

摘要

Panels of aluminum alloy sheets, framed by side and end stiffeners, were subjected to combined loading by means of offset knife edges applying loads to top and bottom end plates with reacting forces against the end plates supplied by laterally acting rollers. The test specimens were 17S-T aluminum alloy shoots 0.040 inch thick in panels of 10-inch width and three different lengths (approximately 10, 26, and 30 inch). Data were obtained for the bowing of transverse and longitudinal ribs of rectangular cross section and varying depths mounted on one side of the sheet only, for several ratios of compression to shear loads. Limiting values of the moments of inertia were calculated from these measurements. The experimental values exceed the theoretical values given by Timoshenko for the case of simply supported sheets with uniformly distributed boundary stresses. The work reported includes measurements of the effective shear moduli of the nine test panels with and without ribs. These data are compared with values published by Lahdo and Wagner.