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Stroud, W. J.

Publications and source records attributed to Stroud, W. J..

28 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Minimum-mass design of filamentary composite panels under combined loads: Design procedure based on a rigorous buckling analysis

A procedure is presented for designing uniaxially stiffened panels made of composite material and subjected to combined inplane loads. The procedure uses a rigorous buckling analysis and nonlinear mathematical programing techniques. Design studies carried out with the procedure consider hat-stiffened and corrugated panels made of graphite-epoxy material. Combined longitudinal compression and shear and combined longitudinal and transverse compression are the loadings used in the studies. The capability to tailor the buckling response of a panel is also explored. Finally, the adequacy of another, simpler, analysis-design procedure is examined.

Stroud, W. J.↗
NASA NTRS1976

Minimum-mass design of filamentary composite panels under combined loads: Design procedure based on simplified buckling equations

An analytical procedure is presented for designing hat stiffened and corrugated panels made of composite material and subjected to longitudinal (in the direction of the stiffeners) compression and shear loadings. The procedure is based on nonlinear mathematical programming techniques and a simplified set of buckling equations. Design requirements considered are buckling, strength, and extensional and shear stiffness. The effects of specified thickness, variation of cross-section dimensions, stiffness requirements, local buckling boundary conditions, and the effect of combined compression and shear loadings are shown.

Stroud, W. J.↗
NASA NTRS1974

Automated structural design with aeroelastic constraints - A review and assessment of the state of the art

A review and assessment of the state of the art in automated aeroelastic design is presented. Most of the aeroelastic design studies appearing in the literature deal with flutter, and, therefore, this paper also concentrates on flutter. The flutter design problem is divided into three cases: as isolated flutter mode, neighboring flutter modes, and a hump mode which can rise and cause a sudden, discontinuous change in the flutter velocity. Synthesis procedures are presented in terms of techniques that are appropriate for problems of various levels of difficulty. Current trends, which should result in more efficient, powerful and versatile design codes, are discussed. Approximate analysis procedures and the need for simultaneous consideration of multiple design requirements are emphasized.

Stroud, W. J.↗
NASA NTRS1972

Selective reinforcement of wing structure for flutter prevention.

The results of an analytical study are presented on the use of boron polyimide filamentary composite material for the purpose of increasing the flutter speed of a simple titanium full depth sandwich wing structure designed for strength. The results clearly demonstrate that selective reinforcement of wing surfaces, using judiciously placed filamentary composites, promises sizable mass savings in the design of advanced aircraft structures.

Cooper, P. A.↗
NASA NTRS1972

Automated preliminary design of simplified wing structures to satisfy strength and flutter requirements

A simple structural model of an aircraft wing is used to show the effects of strength (stress) and flutter requirements on the design of minimum-weight aircraft-wing structures. The wing is idealized as an isotropic sandwich plate with a variable cover thickness distribution and a variable depth between covers. Plate theory is used for the structural analysis, and piston theory is used for the unsteady aerodynamics in the flutter analysis. Mathematical programming techniques are used to find the minimum-weight cover thickness distribution which satisfies flutter, strength, and minimum-gage constraints. The method of solution, some sample results, and the computer program used to obtain these results are presented. The results indicate that the cover thickness distribution obtained when designing for the strength requirement alone may be quite different from the cover thickness distribution obtained when designing for either the flutter requirement alone or for both the strength and flutter requirements concurrently. This conclusion emphasizes the need for designing for both flutter and strength from the outset.

Stroud, W. J.↗