Effect of Aging on Mechanical Properties of Aluminum-Alloy Rivets (open access)

Effect of Aging on Mechanical Properties of Aluminum-Alloy Rivets

"Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24s, 17s, and a17s of the duralumin type and 53s of the magnesium-silicide type" (p. 353).
Date: February 7, 1941
Creator: Roop, Frederick C.
System: The UNT Digital Library
Shear lag in box beams methods of analysis and experimental investigations (open access)

Shear lag in box beams methods of analysis and experimental investigations

The bending stresses in the covers of box beams or wide-flange beams differ appreciably from the stresses predicted by the ordinary bending theory on account of shear deformation of the flanges. The problem of predicting these differences has become known as the shear-lag problem. The first part of this paper deals with methods of shear-lag analysis suitable for practical use. The second part of the paper describes strain-gage tests made by the NACA to verify the theory. Three tests published by other investigators are also analyzed by the proposed method. The third part of the paper gives numerical examples illustrating the methods of analysis. An appendix gives comparisons with other methods, particularly with the method of Ebner and Koller.
Date: March 7, 1941
Creator: Kuhn, Paul & Chiarito, Patrick T.
System: The UNT Digital Library
Flutter calculations in three degrees of freedom (open access)

Flutter calculations in three degrees of freedom

From Summary: "The present paper is a continuation of the general study of flutter published in NACA reports nos. 496 and 685. The paper is mainly devoted to flutter in three degrees of freedom (bending, torsion, and aileron) for which a number of selected cases have been calculated and presented in graphical form. The results are analyzed and discussed with regard to the effects of structural damping, of fractional-span ailerons, and of mass-balancing. The analysis shows that more emphasis should be put on the effect of structural damping and less on mass-balancing."
Date: June 7, 1941
Creator: Theodorsen, Theodore & Garrick, I. E.
System: The UNT Digital Library