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Small Bending and Stretching of Sandwich-Type Shells

Description: "A theory has been developed for small bending and stretching of sandwich-type shells. This theory is an extension of the known theory of homogeneous thin elastic shells. It was found that two effects are important in the present problem, which are not normally of importance in the theory of curved shells: (1) the effect of transverse shear deformation and (2) the effect of transverse normal stress deformation" (p. 1).
Date: 1950
Creator: Reissner, Eric
Partner: UNT Libraries Government Documents Department

Static Longitudinal Stability Characteristics of a Series of 90-Millimeter Artillery Shells at Mach Numbers of 0.8, 0.9, 1.0, and 1.2

Description: Wind-tunnel tests have been made to determine the static longitudinal stability of several models of a short-range artillery shell at Mach numbers of 0.8, 0.9, 1.0, and 1.2. The results of the tests indicated that the best of the spool-shaped shells was statically stable in pitch at all test Mach numbers for an angle-of-attack range up to about 10 degrees. The best of the finned shells was stable to a maximum angle of attack of about 6 degrees. The addition of a probe to the nose of the finned shells resulted in increased static longitudinal stability at the highest Mach numbers tested and in a large decrease in the axial-force coefficients at all Mach numbers.
Date: April 10, 1956
Creator: Spooner, Stanley H.
Partner: UNT Libraries Government Documents Department

Experimental stress analysis of stiffened cylinders with cutouts: Shear load

Description: A cylindrical semimonocoque shell of circular cross section was mounted as a cantilever and loaded by a direct shear at the tip. The cylinder was tested with no cutout, with a rectangular cutout on the tension side, and with the cutout centered on the neutral axis on one side of the cylinder. The cutout was successively enlarged through six sizes varying from 30 degrees to 130 degrees in circumference and from 1 and 2 bays in length. Strain measurements were made with resistance-type wire strain gages near the cutout on the stringers, the skin, and the rings for each case, and the stresses obtained are presented in tables. (author).
Date: July 1954
Creator: Schlechte, Floyd R. & Rosecrans, Richard
Partner: UNT Libraries Government Documents Department

Loads Imposed on Intermediate Frames of Stiffened Shells

Description: "The loads imposed on intermediate frames by the curvature of the longitudinal and by the diagonal-tension effects are treated. A new empirical method is proposed for analyzing diagonal-tension effects. The basic formulas of the pure diagonal-tension theory are used, and the part of the total shear S carried by diagonal tension is assumed to be given the expression S (sub DT) = S (1-tau sub o/tau)(sup n) where tau (sub o) is the critical shear stress, tau the total (nominal shear stress), and n = 3 - sigma/tau where sigma is the stress in the intermediate frame. Numerical examples illustrate all cases treated" (p. 1).
Date: February 1939
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

On the Mechanism of Buckling of a Circular Cylindrical Shell Under Axial Compression

Description: The present paper deals with the buckling of a circular cylindrical shell under axial compression from the viewpoint of energy and the characteristics of deformation. It is shown first, both theoretically and experimentally, that the reason why the buckling of a cylindrical shell is quite different from that of a flat plate is attributable to the existence of a nearly developable surface far apart from the original cylindrical surface. Based upon this result, the experimental fact that the buckling is really not general but local, that is, that the buckled region is limited axially to a range of 1.5 times the wave length of the lobe, is explained by the theoretical result that the minimum buckling load is smaller in the local buckling than in the general buckling case.
Date: July 1955
Creator: Yoshimura, Yoshimaru
Partner: UNT Libraries Government Documents Department

Notes on the Foundations of the Theory of Small Displacements of Orthotropic Shells

Description: Note presenting a survey that has been made of the various systems of equations which have been given in the literature for the analysis of small deflections of thin elastic shell. A new system of equations has been derived for the analysis of shells, which includes the effects of transverse shear and normal stresses.
Date: March 1949
Creator: Hildebrand, F. B.; Reissner, E. & Thomas, G. B.
Partner: UNT Libraries Government Documents Department

A Simplified Method of Elastic-Stability Analysis for Thin Cylindrical Shells 1: Donnell's Equation

Description: "The equation for the equilibrium of cylindrical shells introduced by Donnell in NACA Technical Report no. 479 to find the critical stresses of cylinders in torsion is applied to find critical stresses for cylinders with simply supported edges under other loading conditions. It is shown that by this method solutions may be obtained very easily and the results in each case may be expressed in terms of two nondimensional parameters, one dependent on the critical stress and the other essentially determined by the geometry of the cylinder. The influence of boundary conditions related to edge displacements in the shell median surface is discussed" (p. 1).
Date: June 1947
Creator: Batdorf, S. B.
Partner: UNT Libraries Government Documents Department

Stability of the Cylindrical Shell of Variable Curvature

Description: "This report is a first attempt to devise a calculation method for representing the buckling behavior of cylindrical shells of variable curvature. The problem occurs, for instance, in dimensioning wing noses, the stability of which is decisively influenced by the variability of curvature. The calculation is made possible by simplifying the stability equations (permissible for the shell of small curvature) and by assuming that the curvature 1/R as a function of the arc lengths can be represented by a very few Fourier terms" (p. 1).
Date: July 1951
Creator: Marguerre, Karl
Partner: UNT Libraries Government Documents Department

Stress Analysis of Circular Semimonocoque Cylinders With Cutouts by a Perturbation Load Technique

Description: "A method is presented for analyzing the stresses about a cutout in a circular cylinder of semimonocoque construction. The method involves the use of so-called perturbation solutions which are superposed on the stress distribution that would exist in the structure with no cutout in such a way as to give the effects of a cutout. The method can be used for any loading case for which the structure without the cutout can be analyzed and is sufficiently versatile to account for stringer and shear reinforcement about the cutout" (p. 1).
Date: September 1954
Creator: McComb, Harvey G., Jr.
Partner: UNT Libraries Government Documents Department

A Low-Speed Investigation of the Magnus Effects on a Sting-Mounted Model of a Typical Mortar Shell

Description: Memorandum presenting an investigation made in the stability tunnel with a 2.3-scale spinning model of a typical mortar shell. The tests were made to measure the aerodynamic forces and moments acting on a typical spinning mortar shell. Results regarding the basic configuration, effect of changes in tail configuration, effect of changes in the nose configuration, and comparison of mortar shell and antisubmarine rocket are provided.
Date: January 2, 1957
Creator: Lichtenstein, Jacob H.
Partner: UNT Libraries Government Documents Department

Basic Differential Equations in General Theory of Elastic Shells

Description: "The shell shall be considered as a three-dimensional continuous medium; for the coordinate surface, the middle surface of the shell shall be assumed parallel to the bounding surfaces. Let alpha and beta be the curvilinear orthogonal coordinates of this surface, coinciding with the lines of principal curvatures, and gamma the distance along the normal from the point (alpha,beta) of the coordinate surface to any point (alpha, beta, gamma) of the shell" (p. 1).
Date: February 1951
Creator: Vlasov, V. S.
Partner: UNT Libraries Government Documents Department

Principle and Application of Complementary Energy Method for Thin Homogeneous and Sandwich Plates and Shells With Finite Deflections

Description: Note presenting the principle of complementary energy in the nonlinear elasticity theory, which is shown to be derivable from the principle of potential energy by a Legendre type of transformation. The expression of the complementary energy is derived for homogeneous and sandwich plates and shells with large deflections. The stress-strain relations are derived for homogeneous shells, sandwich plates, and sandwich shells.
Date: February 1952
Creator: Wang, Chi-Teh
Partner: UNT Libraries Government Documents Department

Torsional Stiffness of Thin-Walled Shells Having Reinforcing Cores and Rectangular, Triangular, or Diamond Cross Section

Description: A theoretical investigation is presented of the torsional stiffness of thin-walled aerodynamic surfaces filled with cores which stabilize the skins. Rectangular, slender triangular, and slender diamond cross sections are considered. Results for the torsional stiffness constants are shown graphically.
Date: October 1956
Creator: McComb, Harvey G., Jr.
Partner: UNT Libraries Government Documents Department

Calculation of Load Distribution in Stiffened Cylindrical Shells

Description: "Thin-walled shells with strong longitudinal and transverse stiffening (for example, stressed-skin fuselages and wings) may, under certain simplifying assumptions, be treated as static systems with finite redundancies. In this report the underlying basis for this method of treatment of the problem is presented and a computation procedure for stiffened cylindrical shells with curved sheet panels indicated. A detailed discussion of the force distribution due to applied concentrated forces is given, and the discussion illustrated by numerical examples which refer to an experimentally determined circular cylindrical shell" (p. 1).
Date: June 1938
Creator: Ebner, H. & K├Âller, H.
Partner: UNT Libraries Government Documents Department

Torsional Stiffness of Thin-Walled Shells Having Reinforcing Cores and Rectangular, Triangular, or Diamond Cross Section

Description: "A theoretical investigation has been made of the Saint-Venant torsion of certain composite bars. These bars are composed of two materials -- one material in the form of a thin-walled cylindrical shell and the other material in the form of a core which fills the interior of the shell and is bonded to it. An approximate boundary-value problem is formulated on assumptions similar to those of the theory of torsion of hollow thin-walled shells (Bredt theory)" (p. 771).
Date: June 7, 1956
Creator: McComb, Harvey G., Jr.
Partner: UNT Libraries Government Documents Department

Full-scale investigation of cooling shroud and ejector nozzle for a turbojet engine: afterburner installation

Description: From Summary: "A full-scale ejector cooling investigation was made on a turbojet engine - afterburner installation in the NACA Lewis altitude wind tunnel. Ejector performance was studied at primary exhaust-gas temperatures from 2700 degrees to 3400 degrees R (corresponding to ejector temperature ratios from 2.0 to 5.0), primary pressure ratios from 1.79 to 3.4, secondary air flows up to 29 percent of the primary gas flow, and for diameter ratios from 1.08 to 1.42 and spacing ratios from 0.04 to 1.16. In addition, variations were made in the primary exhaust-nozzle area."
Date: December 17, 1951
Creator: Wallner, Lewis E. & Jansen, Emmert T.
Partner: UNT Libraries Government Documents Department

Characterization of Russian ballistic furnace shells, February, 1999, batch

Description: This report documents the characterization of the latest batch of shells produced in the Ballistic Furnace System at the Lebedev Physical Institute, Moscow, Russia, that we received in mid-February, 1999. The batch consisted of three cassettes containing 36 shells in each cassette. An initial sphericity measurement was done, each shell was weighed, and shells were selected that were spherical enough to run on the Sphere Mapper AFM.
Date: April 2, 1999
Creator: Fearon, E
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the effect of spin on the aerodynamic characteristics of a 60-millimeter T-24 mortar shell with several tail-fin configurations

Description: Report presenting an investigation in the high-speed tunnel to determine the effect of spin on the aerodynamic characteristics of a 60-millimeter T-24 mortar shell with several different tail-fin configurations. Tests were made at a range of airspeeds, speeds of rotation, and angles of attack. Results regarding forced-spin tests, free-spin tests, and zero-spin tests are provided.
Date: March 21, 1957
Creator: Kemp, William B., Jr. & Hayes, William C., Jr.
Partner: UNT Libraries Government Documents Department

Weight-Strength Studies of Structures Representative of Fuselage Construction

Description: Note presenting weight-strength plots for circular cylindrical shells in bending. The ring-stiffened shell, the longitudinally stiffened shell, and shells constructed of waffle-like or sandwich-type plates are compared in order to evaluate the effect of type of stiffening on bending strength, and shells of various materials are compared to evaluate the effect of material properties. The effect of shear loads on the bending strength of cylinders is considered.
Date: October 1957
Creator: Peterson, James P.
Partner: UNT Libraries Government Documents Department

A Simplified Method of Elastic-Stability Analysis for Thin Cylindrical Shells

Description: "This paper develops a new method for determining the buckling stresses of cylindrical shells under various loading conditions. In part I, the equation for the equilibrium of cylindrical shells introduced by Donnell in NACA report no. 479 to find the critical stresses of cylinders in torsion is applied to find critical stresses for cylinders with simply supported edges under other loading conditions. In part II, a modified form of Donnell's equation for the equilibrium of thin cylindrical shells is derived which is equivalent to Donnell's equation but has certain advantages in physical interpretation and in ease of solution, particularly in the case of shells having clamped edges" (p. 285).
Date: March 20, 1947
Creator: Batdorf, S. B.
Partner: UNT Libraries Government Documents Department