Impact Damage Tolerance of Thin Wall Composite STRUTS
An experimental investigation was made to study the impact damage tolerance of thin wall composite struts made of both brittle epoxy and toughtened epoxy based composite materials.
Impact↗
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Repair of weld defects in thin-walled stainless steel tubes
Hand-operated tool repairs weld defects in large-diameter, thin-walled stainless steel tubes. Tool consists of a three-roll external planisher and an internal backup mandrel, both hydraulically pressurized by hand pumps, and an external restraining mandrel, which keeps the tube from turning during the planishing operations.
Fiorelli, F.↗
Method for precision forming of low-cost, thin-walled slotted waveguide arrays for the SPS
A method for the precision-forming of thin-walled, slotted-waveguide arrays was devised. Models were constructed with temporary tools and evaluated. The application of the method to the SPS requirements is discussed.
Brown, W. C.↗
Critical stress of thin-walled cylinders in axial compression
Empirical design curves are presented for the critical stress of thin-walled cylinders loaded in axial compression. These curves are plotted in terms of nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75. The test data obtained from various sources follow the general trend of the theoretical curve for cylinders with clamped edges, agreeing closely with the theory in the case of short cylinders, but falling considerably below the theoretical results for long cylinders. The discrepancy in the case of long cylinders increases with increasing values of the ratio of radius to wall thickness. Plotting curves for different values of this ratio reduces the scatter in the test data and a certain degree of correlation with theory is achieved. Advantage is taken of this correlation to obtain estimated design curves for cylinders with simply supported edges, for which little experimental information is available. (author)
Batdorf, S B↗
Critical stress of thin-walled cylinders in axial compression
Empirical design curves are presented for the critical stress of thin-wall cylinders loaded in axial compression. These curves are plotted in terms of the nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75.
Batdorf, S B↗
The Twisting of Thin-walled, Stiffened Circular Cylinders
On the basis of the present investigation of the twisting of thin-walled, stiffened cylinders the following conclusions can be reached: 1) there is as yet no generally applicable formula for the buckling moment of the skin; 2) the mathematical treatment of the condition of the shell after buckling of the skin is based on the tension-field theory, wherein the strain condition is considered homogenous.
Schapitz, E↗
Stability of cylindrical shells. An analytical and experimental investigation of the effects of large prebuckling deformations on the buckling of clamped thin-walled cylindrical shells subjected to axial loading and internal pressure Semiannual pro
Prebuckling deformation effects on clamped, thin- walled cylindrical shell buckling due to axial loading and internal pressure
DEFORMATION↗
Interactive buckling of thin-walled structural components under static and dynamic loads
Recent advances in the study of interactive buckling of thin walled structural components achieved with the aid of finite strip technique used in conjunction with the theory of mode interaction are summarized. The interaction of the primary local mode with Euler buckling (in columns) and flexural torsional buckling (in columns and beams) is of primary interest. The interaction of two companion local modes with the overall mode is also considered briefly for the columns with doubly symmetric cross sections. The effect of dynamic loads in the form of suddenly applied and compression is also investigated.
Sridharan, S.↗
An analytical and experimental investigation of the effects of large prebuckling deformations on the buckling of clamped thin-walled circular cylindrical shells subjected to axial loading and internal pressure
Prebuckling deformations effect on buckling of clamped thin walled circular cylindrical shells under axial loading and internal pressure
Evan-Iwanowski, R. M.↗
Effects of surface and through cracks on failure of pressurized thin-walled cylinders of 2014-T6 aluminum
Investigating effects of surface and through cracks on failure of pressurized thin-walled aluminum cylinders
Pierce, W. S.↗
Bending response of thin-walled laminated composite cylinders
Closed-form linear response solutions are presented for the bending response of thin-walled laminated composite cylinders. Displacements and intralaminar stresses are computed using the Donnell theory, and interlaminar stresses are computed using 3D equilibrium equations of elasticity. Laminates with stacking sequencies and an aluminum cylinder are used to illustrate the displacement response, intralaminar, and interlaminar stresses for two length-to-radius ratios of 1 and 5. Data obtained indicate that if only fiber breakage causes ultimate failure, material failure will occur on the compression side of the cylinders, at the ends, due to fiber compression. The interlaminar normal stress is an order of magnitude smaller than the interlaminar shear stresses and it is not likely to initiate failure.
Fuchs, H. P.↗
Stresses In And Near A Bend In A Thin-Walled Duct
Report describes computational study of distributions of stresses in and near 90 degrees bend in thin-walled duct subject to various applied loads. Purpose of study to help satisfy need for more accurate knowledge of local concentrations of stresses caused by loads: such knowledge makes possible to design light-weight ducts to survive reasonably foreseeable operating conditions with some degree of reliability. Also guides selection of locations for mounting strain gauges to measure local stresses for comparison with computed values, contributing to refinement of theoretical concepts and computational techniques.
Min, J. B.↗
Study made of thin-walled pipe response to turbulent fluids
Report summarizes the experimental and theoretical data on the vibrational response of thin-walled pipe sections to the wall pressure field applied within them by a fully developed turbulent fluid flow. The predicted responses were in good agreement with previous data obtained.
Clinch, J. M.↗
Stability of Thin-Walled Tubes Under Torsion
In this report a theoretical solution is developed for the torsion on a round thin-walled tube for which the walls become unstable. The results of this theory are given by a few simple formulas and curves which cover all cases. The differential equations of equilibrium are derived in a simpler form than previously found, it being shown that many items can be neglected.
Donnell, L H↗
Theory of thin-walled rods
Starting with the Love equations for bending of extensible shells, "principal stress states" are sought for a thin-walled rod of arbitrary but open cross section. Principal stress states exclude those local states arising from end conditions which damp out with distance from the ends. It is found that for rods of intermediate length, long enough to avoid local bending at a support, and short enough that elementary torsion and bending are not the most significant stress states, four principal states exist. Three of these states are associated with the planar distribution of axial stress and are equivalent to the engineering theory of extension and bending of solid sections. The fourth state resembles that which has been called in the literature "bending stress due to torsional", except that cross sections are permitted to bend and the shear along the center line of the cross section is permitted to differ from zero.
LOADS AND STRESSES, STRUCTURAL - TENSION↗
Analysis of curved thin-walled shells of revolution.
Boundary value problem solution governed by system of partial differential equations applied to analysis of curved thin walled shells of revolution
Kalnins, A.↗
Thin-walled composite beams under bending, torsional, and extensional loads
Symmetric and antisymmetric layup graphite-epoxy composite beams with thin-walled rectangular cross sections are fabricated using an autoclave molding technique and tested under bending, torsional, and extensional loads. The bending slope and elastic twist at a station are measured using an optical system, and the results correlated with predicted values from a simple beam analysis as well as a refined finite element analysis. A symmetric ply layup results in bending-twist coupling whereas an antisymmetric layup causes extension-twist coupling. Simple analytical results with plane-stress assumption agree better with measured data as well as finite element predictions than with plane-strain assumption. For symmetric layup beams, the bending-induced twist and torsion-induced bending slope are predicted satisfactorily using simple analytical solution. Correlations with measured data, however, are generally improved using a finite element solution. For antisymmetric beams, axial force-induced twist is predicted satisfactorily by both methods.
Chandra, Ramesh↗
Isotropic thin-walled pressure vessel experiment
The objectives are: (1) to investigate the stress and strain distributions on the surface of a thin walled cylinder subject to internal pressure and/or axial load; and (2) to relate stress and strain distributions to material properties and cylinder geometry. The experiment, supplies, and procedure are presented.
Denton, Nancy L.↗