Vibration and Aerodynamic Buckling Experiments for Blunt Truncated Conical Shells with Ring-supported Edges

Vibration and Aerodynamic Buckling Experiments for Blunt Truncated Conical Shells with Ring-supported Edges

Author: Robert Miserentino

Publisher:

Published: 1972

Total Pages: 44

ISBN-13:

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The vibration and buckling characteristics of a series of 140 deg ring-supported conical shells have been investigated experimentally and analytically. Experimental results were obtained from 14 conical shells, each attached to a solid nose cap at the small end. The large (base) end was either free or attached to a solid ring of rectangular cross section. The size of the solid base rings of rectangular cross section was systematically varied to provide a wide range of edge restraint. Shell buckling was induced by aerodynamic loading at a Mach number of 3; the vibration data were obtained prior to the wind tunnel tests. The experimental vibration data indicated that the size of the base rings had a pronounced effect on the magnitude of the frequencies and on the frequency spectrum. For vibration modes having less than two circumferential waves, the frequencies descreased with increasing ring size; whereas, for modes with several circumferential waves, the frequencies initially increased rapidly with ring size and then became relatively insensitive to further increases in ring size. This latter behavior was similar to the trend exhibited by the variation of buckling pressure with ring size. The experimental results were in excellent qualitative agreement with theoretical results and indicated that current shell-of-revolution analyses are adequate for predicting the vibration and buckling behavior of ring-supported shells, at least for the simple isotropic shells considered in this investigation.


Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1973

Total Pages: 1040

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.


Alloy Softening in Group VIA Metals Alloyed with Rhenium

Alloy Softening in Group VIA Metals Alloyed with Rhenium

Author: Joseph R. Stephens

Publisher:

Published: 1970

Total Pages: 892

ISBN-13:

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An investigation was conducted to determine the effect of temperature and composition on alloy softening in group VIA metals Cr, Mo, and W alloyed with Re. Results showed that alloy softening was similar in all three alloy systems occurring at homologous temperatures less than 0.16 and at Re concentrations less than 16 atom percent. Rhenium content required to produce a hardness minimum diminished rapidly in all three systems with increasing test temperature. The similarities in hardness behavior in these three alloy systems suggesat common softening mechanism which may arise from lowering the Peierls stress.