Search NASA⌕ Search

SEARCH · Search NASA

Results for “AXIAL COMPRESSION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1962

GENERAL INSTABILITY OF ORTHOGONALLY STIFFENED CYLINDRICAL SHELLS

Earlier research at the National Aeronautics Research Institute (N.L.R.), Amsterdam, which forms the basis of recent work is reviewed. This early work refers to 2 schemes: the orthotropic shell and, in view of buckling modes where the half wave length is of the order of the ring distance, the shell with continuously distributed stringers and discrete rings. Linear theory is considered to be adequate for these structures, where the imperfections are small in comparison to the height of the ring sections. Recent developments account for pressure difference in addition to axial compression, for the correct stiffness matrix of skin panels in the post-buckling stage and for stringer bending due to hoop stresses in the skin, which are of importance as has been shown by the investigation of the post-buckling behaviour. Numerical data for the stiffness matrix of skin panels have been established. Numerical evaluation of the stability equation has not been performed as yet.

SHELL STABILITY↗
NASA NTRS1962

ELASTIC STABILITY OF SIMPLY SUPPORTED CORRUGATED CORE SANDWICH CYLINDERS

Theoretical buckling coefficients are obtained for the general instability of simply supported, corrugated core sandwich circular cylinders under combined loads with the core oriented parallel to the longitudinal axis of the cylinder. Buckling curves are presented for axial compression, external lateral pressure, torsion, and some typical interactions. The differential equations of equilibrium used to obtain the buckling equations were derived from the small deflection equations of Stein and Mayer which include the effect of deformation due to transverse shear. These equations are solved by Galerkin's equation. Remarks are made concerning the probable validity of the results of the small deflection theory for sandwich shells.

SHELL STABILITY↗
NASA NTRS1962

Buckling of Orthotropic and Stiffened Conical Shells

Donnell type stability equations for thin circular orthotropic conical shells are presented and solved for external pressure, axial compression and combined loading. The solution is likewise applied to stiffened conical shells. Correlation with equivalent cylindrical shells yields a simple approximate stability analysis for orthotropic or ring-stiffened conical shells under hydrostatic pressure. The general instability of stiffened conical shells under hydrostatic pressure is also analysed by a more accurate approach. Preliminary experimental results for buckling of ring-stiffened conical shells under hydrostatic pressure are presented and discussed.

CONICAL SHELL↗
NASA NTRS1966

Design of thick honeycomb core structures

The demand for weight reduction in flight vehicles suggests the use of lightweight sandwich structures. Several factors must be considered to obtain minimum-weight sandwich constructions. High-strength thin facings combined with lightweight thick core can offer a highly efficient structure when careful consideration is given to practical proportions between facings and core, edge design details, and manufacturing techniques. This paper discusses design approaches to relatively thick-core sandwich constructions. 'A large cylindrical structure subjected to axial compression loading and panel-type structures requiring low deflection under transverse loads are briefly analyzed. The selection of structural adhesives for thick-core structures and manufacturing considerations also are discussed.

SANDWICH CONSTRUCTION↗
NASA NTRS1969

Shell design computer program

Computer program determines the useful strength of a thin-walled shell once it has been wrinkled. It can be used as an analytical tool by designers to determine how much wrinkling or deformation a shell can withstand when subjected to axial compression and bending loads.

Greenbaum, G. A.↗
NASA NTRS1969

Prestressed brittle structures.

Prestressed beams, columns and plates nonlinear response, statistical behavior and transverse cracking under axial compression, describing strength and stiffness

Barnett, R. L.↗
NASA NTRS1971

An experimental study of the strength and stability of thin monocoque shells with reinforced and unreinforced rectangular cutouts

Axial compression tests were run on eleven thin-walled aluminum cylinders having rectangular cutouts. Various types of reinforcement were used around the cutouts, and some tests were run with no reinforcement. The test results are compared with the cylinder buckling loads prior to installation of the cutouts (obtained without damaging the cylinder by using a buckle-capture technique), and correlated with computer-predicted failure loads. The latter were based on the use of the STAGS computer program. For thin cylinders such as these, the test and computer-based analysis shows that for small to moderate size cutouts, reinforcement of the cutout is of no benefit unless the cylinder is of extremely high (geometrical) quality. For cylinder quality and cutout size where reinforcement is beneficial, the relative merits of the various reinforcement configurations are discussed, and an empirical basis for design is proposed.

Holmes, A. M. C.↗
NASA NTRS1972

Some applications of NASTRAN to the buckling of thin cylindrical shells with cutouts

The buckling of isotropic and waffle-stiffened circular cylinders with and without cutouts was studied using NASTRAN's Rigid Format 5 for the case of axial compressive loading. The results obtained for the cylinders without cutouts are compared with available reference solutions. The results for the isotropic cylinders containing a single circular cutout with selected radii are compared with available experimental data. For the waffle-stiffened cyclinder, the effect of two diametrically opposed rectangular cutouts was studied. A DMAP alter sequence was used to permit the necessary application of different prebuckling and buckling boundary conditions. Advantage was taken of available symmetry planes to formulate equivalent NASTRAN model segments which reduced the associated computational cost of performing the analyses. Limitations of the applicability of NASTRAN for the solution of problems with nonlinear characteristics are discussed.

Williams, J. G.↗
NASA NTRS1972

The continuously supported rail subjected to an axial force and a moving load.

The recent practice of welding railroad rails to each other suggests that considerable axial compression forces may be induced in the rails because of a rise in temperature. This in turn may reduce the critical velocity for the track to the range of operational velocities of modern high-speed trains. The purpose of the paper is to demonstrate that this is indeed a possibility.

Kerr, A. D.↗