Abstract:
Three cellulose-nitrate model wings, identical except I0r rib flexibility, have been tested under conditions reproducing typical engine loads. Stress distributions have been found experimentally by means of electrical resistance strain-gauges. The distribution due to an abrupt change of torsion has been compared with a theory by Williams, and that due to an abrupt change of shear with a theory by Taylor. Local stresses at the engine nacelle are found to be appreciably higher in practice than would have been predicted by either of these theories. The discrepancies, moreover, are found to increase with rib flexibility.