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  • STRUCTURAL MECHANICS  (2,554)
  • Fluid Mechanics and Thermodynamics
  • 2020-2020
  • 1975-1979  (1,054)
  • 1970-1974  (1,514)
  • 1945-1949  (45)
Collection
Years
Year
  • 1
    Publication Date: 2005-11-27
    Description: Fatigue crack length relationship with aircraft inspection intervals and structural reinforcement, high strength materials, and aircraft usage effects
    Keywords: STRUCTURAL MECHANICS
    Type: NASA AIRCRAFT SAFETY AND OPERATING PROBL., VOL. 1 1971; P 391-401
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  • 2
    Publication Date: 2005-11-27
    Description: Vibration design and test criteria considerations for space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 423-450
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  • 3
    Publication Date: 2005-11-27
    Description: Optimization of payload for space shuttle by reducing structural loading and weight
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 315-332
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  • 4
    Publication Date: 2005-11-27
    Description: Buffet response of straight wing and delta wing model of space shuttle launch configuration
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 265-291
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  • 5
    Publication Date: 2005-11-27
    Description: Transonic wind tunnel investigation of flow characteristics and pressure fluctuation of space shuttle launch and reentry configurations
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 293-314
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  • 6
    Publication Date: 2005-11-27
    Description: Parameters contributing to aeroelastic problems in thermal protection of space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 247-264
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  • 7
    Publication Date: 2005-11-27
    Description: Application of research in panel flutter and boundary layer thickness to space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 231-245
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  • 8
    Publication Date: 2005-11-27
    Description: Transonic flutter and buffeting for elastic wind tunnel models of straight wing proposed for space shuttles
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 201-229
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  • 9
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Problems in propellant dynamics including pipeline dynamics, effect of bubble location, turbulent flow, and effect of tilting tank on liquid oscillation frequency
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 95-120
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  • 10
    Publication Date: 2005-11-27
    Description: Dynamic response of thermal protection system panel for space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LANGLEY RES. CENTER NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 49-93
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  • 11
    Publication Date: 2005-11-27
    Description: Vibration tests of space shuttle panels at room temperature
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 27-48
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  • 12
    Publication Date: 2005-11-27
    Description: Vibration studies of dynamic scale model of space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: NASA SPACE SHUTTLE TECHNOL. CONF., VOL. 3 APR. 1971; P 1-25
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  • 13
    Publication Date: 2005-11-27
    Description: Theoretical calculations and holographic measurements on transverse deflections of astronomical mirror blank
    Keywords: STRUCTURAL MECHANICS
    Type: NASA, WASHINGTON OPT. TELESCOPE TECHNOL. 1970; P 287-270
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  • 14
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Dynamic analysis to predict space vehicle response to atmospheric disturbances with reference to space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 331-348
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  • 15
    Publication Date: 2005-11-27
    Description: Load alleviation and structural mode control potential for space shuttle vehicle
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 349-363
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  • 16
    Publication Date: 2005-11-27
    Description: Basic vibration characteristics and random response in thin panels
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 43-57
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  • 17
    Publication Date: 2005-11-27
    Description: Communications satellite antenna structure dynamic response to random loads in launch environment
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LEWIS RES. CENTER SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 301-329
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  • 18
    Publication Date: 2005-11-27
    Description: Staging dynamics for piggyback space shuttles
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LEWIS RES. CENTER SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 123-142
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  • 19
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Lifting and control surface flutter on space shuttles
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 177-198
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  • 20
    Publication Date: 2005-11-27
    Description: Control systems for vibration isolation of large structures and vacuum chambers
    Keywords: STRUCTURAL MECHANICS
    Type: NASA, WASHINGTON OPT. TELESCOPES TECHNOL. 1970; P 733-749
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  • 21
    Publication Date: 2005-11-27
    Description: Thermal environment effects on alignment behavior of structural joints and assemblies of reentry vehicle and Mars landing module
    Keywords: STRUCTURAL MECHANICS
    Type: OPT. TELESCOPE TECHNOL. 1970; P 335-349
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  • 22
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Vibration response and acoustic fatigue characteristics of space shuttle thermal protection system design concepts
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 273-284
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  • 23
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Dynamic model for obtaining response data for space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 29-42
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  • 24
    Publication Date: 2005-11-27
    Description: Pogo effect influence on aerodynamic phenomena in rocket afterbody
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LEWIS RES. CENTER SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 263-265
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  • 25
    Publication Date: 2005-11-30
    Description: The latest technology for structural analysis in relation to the design tasks that lie ahead for the space shuttle is reviewed. For shell-of-revolution structures, the analysis can be formulated as a one-dimensional problem which is readily solved by using finite-difference or numerical-integration techniques. For more general asymmetric shells, a two-dimensional formulation is required. However, the governing equations are readily formulated and are amenable to solution by finite-difference techniques. For a completely general structural arrangement, such as structural frameworks, recourse is usually made to discretized formulations using finite elements. Of course, the finite-element programs could be used for shell structures, but at a loss in accuracy and increase in computer time compared with the special purpose programs.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA Space Shuttle Technol. Conf.; p 685-725
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  • 26
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Ring reinforcements for damping structural deformation in orthotropic mirror design
    Keywords: STRUCTURAL MECHANICS
    Type: NASA, WASHINGTON OPT. TELESCOPE TECHNOL. 1970; P 283-286
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  • 27
    Publication Date: 2005-11-27
    Description: Finite element method for structural design of astronomical mirrors
    Keywords: STRUCTURAL MECHANICS
    Type: NASA, WASHINGTON OPT. TELESCOPE TECHNOL. 1970; P 249-255
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  • 28
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    In:  CASI
    Publication Date: 2005-11-27
    Description: Transient loading considerations for shuttle design
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LEWIS RES. CENTER SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 79-100
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  • 29
    Publication Date: 2005-11-27
    Description: Assessment of techniques for determining eigenvalues of large systems
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LEWIS RES. CENTER SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 4-27
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  • 30
    Publication Date: 2005-11-27
    Description: Using finite element method in analysis and design of optical space telescopes
    Keywords: STRUCTURAL MECHANICS
    Type: OPT. TELESCOPE TECHNOL. 1970; P 401-415
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  • 31
    Publication Date: 2005-11-27
    Description: Structural analysis for optimal load carrying substrate members of lightweight astronomical mirror
    Keywords: STRUCTURAL MECHANICS
    Type: NASA, WASHINGTON OPT. TELESCOPE TECHNOL. 1970; P 257-280
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  • 32
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    In:  CASI
    Publication Date: 2005-11-27
    Description: User checklist for spacecraft boom selection with review of structural, electrical and mechanical properties
    Keywords: STRUCTURAL MECHANICS
    Type: JPL PROC. OF THE 4TH AEROSPACE MECH. SYMP. 15 JAN. 1970; P 51-54
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  • 33
    Publication Date: 2005-11-27
    Description: Acoustic, vibration, and shock environments in designing orbital telescopes
    Keywords: STRUCTURAL MECHANICS
    Type: OPT. TELESCOPE TECHNOL. 1970; P 389-400
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  • 34
    Publication Date: 2005-11-27
    Description: Coupled structure-propulsion system instability /POGO/ prevention on space shuttle
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. LEWIS RES. CENTER SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 249-262
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  • 35
    Publication Date: 2005-11-27
    Description: Supersonic panel flutter of space shuttle heat shields with flexible supports
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECHNOL. SYMP., VOL. 2 JUL. 1970; P 199-221
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  • 36
    Publication Date: 2005-11-27
    Description: Design and development of deployment fixture for simulated zero gravity testing of large area solar array
    Keywords: STRUCTURAL MECHANICS
    Type: JPL PROC. OF THE 4TH AEROSPACE MECH. SYMP. 15 JAN. 1970; P 83-89
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  • 37
    Publication Date: 2005-11-27
    Description: Mechanical and thermal properties of materials for five spacecraft boom designs
    Keywords: STRUCTURAL MECHANICS
    Type: JPL PROC. OF THE 4TH AEROSPACE MECH. SYMP. 15 JAN. 1970; P 43-45
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  • 38
    Publication Date: 2005-11-27
    Description: Customer opinion of design of aerospace mechanisms
    Keywords: STRUCTURAL MECHANICS
    Type: JPL PROC. OF THE 4TH AEROSPACE MECH. SYMP. 15 JAN. 1970; P 91-94
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  • 39
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    Publication Date: 2005-11-27
    Description: Performance summary and spacecraft applications of booms with future trends
    Keywords: STRUCTURAL MECHANICS
    Type: JPL PROC. OF THE 4TH AEROSPACE MECH. SYMP. 15 JAN. 1970; P 55-72
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  • 40
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    Publication Date: 2006-08-09
    Description: An idealized two-dimensional example of rapid interface flow extension is described. Initially undisturbed dissimilar isotropic, homogeneous, linearly elastic half-spaces are perfectly bonded along the interface y=0. Quantities associated with the half-space or = to 0 are denoted by the prime superscript or the subscripts 3 or 4 while those in y or = to 0 carry the subscripts 1 or 2. At time t=0 adjacent material points at x=0, y= + or - 0 are forced apart horizontally with a constant relative velocity delta v. This results in a zone of bond failure which extends symmetrically along the interface at a constant rate c. The newly created flaw surfaces are in sliding contact resisted by Coulomb friction. The friction coefficient is gamma.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Advan. in Eng. Sci., Vol. 1; p 239-246
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  • 41
    Publication Date: 2006-06-12
    Description: Two efficient concepts built from curved elements were identified, and a data base for tubular panels was developed. The tubular panel failure modes were understood, and the data base for these panels indicated that their performance can be predicted. The concepts are currently being tested in a realistic builtup structure; 157 room temperature tests and 67 hot tests were made with no structural failures, although all of these tests were not at the design load of the structure.
    Keywords: STRUCTURAL MECHANICS
    Type: Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 538-576
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  • 42
    Publication Date: 2006-06-13
    Description: A continuing effort to develop a comprehensive capability for thermal-structural analysis and automated design (sizing) is reviewed. A principal role in the activity is played by the finite element program SPAR which contains both an efficient structural and thermal analysis capability. The benefit of having thermal and structural analyses in the same finite element program is illustrated by the application of SPAR to design calculations for the National Transonic Facility - a cryogenic wind tunnel under construction at Langley. Some experience with large-scale thermal structural analysis problems, particularly the space shuttle orbiter, has led to the identification of some analysis needs. Those needs include automated model generation and data output for lumped parameter thermal analysis, faster solution methods for nonlinear transient heat transfer, automated interpolation of temperature data from a thermal finite element model to a dissimilar structural finite model, and automated techniques to identify the times at which the critical combinations of transient heating and loads occur on a structure.
    Keywords: STRUCTURAL MECHANICS
    Type: Recent Advan. in Structures for Hypersonic Flight, Pt.2; p 897-941
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  • 43
    Publication Date: 2006-06-13
    Description: A comparison study is described which has indicated that the finite element and lumped parameter methods are comparable for steady-state conduction/convection analyses. The finite element model was advantageous because of the ease of model verification with computer graphics. Some problems encountered in constructing compatible thermal and structural models have indicated the need for further methodology developments to automate the transition between thermal and structural analyses. The need for more efficient finite element nonlinear transient algorithms has been cited. With further development in the thermal analysis area, the finite element method offers high potential for an integrated thermal/structural analysis capability.
    Keywords: STRUCTURAL MECHANICS
    Type: Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 851-896
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  • 44
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    Publication Date: 2006-06-13
    Description: With optimized insulation thickness, tank temperatures were always below 311 K (100 F). This conclusion indicated that an aluminum tank could be used with an optimized insulation system if desired. The N2 purged systems were always lighter than CO2 purged systems. The lower condensation temperature was the controlling factor. Closed cell foam systems were lightest. Closed cell foams, in spite of their need for protective outer insulation, produced insulation systems which were lighter than systems which allowed cryodeposition. Foam system durability established for TMAX = 316 K (110 F). Tests for a subsonic application established this durability; higher temperature limit foam durability was unknown at this. An increase in foam TMAX from 316 K (110 F) to 450 K (350 F) potentially decreased TPS mass by 25 percent.
    Keywords: STRUCTURAL MECHANICS
    Type: Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 807-847
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  • 45
    Publication Date: 2006-06-13
    Description: The facilities, testing techniques, and design methods are described for NASA Dryden Flight Research Center. High temperature strain gage technology, realistic flight hardware fabrication, and structural analysis are discussed. A considerable amount of experimental work on hot structure concepts for hypersonic vehicles was performed; all the work is not complete, and there are still problem areas that need to be resolved.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 707-750
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  • 46
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    Publication Date: 2006-06-13
    Description: A study of multiwall TPS as an alternative to LRSI for the space shuttle indicated that vented multiwall, with foil thicknesses limited to those used in multiwall fabricated to date, is some what heavier than LRSI. With reduced foil thicknesses, multiwall TPS may equal the weight of LRSI. Metallic conduction through multiwall TPS transfered less heat than gas conduction or radiation. Radiation heat transfer was greatest at high temperatures; however, the number of layers selected can significantly reduce radiation. At low-to-intermediate temperatures, gas conduction transfered the most heat through multiwall TPS. Gas conduction may be eliminated by evacuation of panels. Oxidation rates required a trade of foil thickness against life.
    Keywords: STRUCTURAL MECHANICS
    Type: Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 671-706
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  • 47
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    Publication Date: 2006-06-13
    Description: The goal of HYTID was to provide a cost effective hypersonic vehicle constructed of near-state-of art systems and structure with sufficient margins to assure no vehicle flight development problems, and to permit concentration of flight operations on hypersonic research with a broad series of experiments carried in a dedicated payload bay or on the exposed surface of the lower aft fuselage.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 601-627
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  • 48
    Publication Date: 2006-06-13
    Description: A lightweight metallic TPS was designed, and two test articles were fabricated, one from Haynes 188 and one from Rene 41. A baseline TPS concept, selected at the beginning of the program, consisted of a Haynes 25 corrugation-stiffened beaded skin surface panel, a specially designed support system, and an insulation system. By optimizing the structure for the design loads and by chem-milling to remove material not needed, the mass of the baseline surface panel was reduced 25%, and the mass of the support structure was reduced 50%. The insulation system mass was reduced 40% by using two types of insulation, each suited to its temperature range, and by eliminating a foul bag which encapsulated the baseline insulation system. These reductions resulted in an overall 35% reduction in mass of the Haynes 188 panel from the baseline Haynes 25 design. Similar reductions were achieved with the Rene 41 system.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 629-669
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  • 49
    Publication Date: 2006-06-13
    Description: The studies to date were encouraging and indicated that materials were available or could be developed to satisfy scramjet requirements. Some of the more promising materials for the critical components were indicated. This information is summarized as follows : (1) radome - Slip cast fused silica is the current candidate, but others are being investigated. One shortcoming of slip cast fused silica is its susceptability to rain damage. (2) inlet leading edges - A refractory metal with a good oxidation protective coating will be required. Tantalum T222 with a Hafnia coating looks promising. (3) inlet ducts - An uninsulated refractory alloy will be required. Columbium F-85 was the best of those considered for the noncircular ducts. (4) external body - The external body temperatures are sufficiently low to permit the use of super alloys. (5) combustor and nozzle - The pyrolytic graphite/silicon carbide coating is very attractive for use in the combustor and nozzle areas.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Recent Advan. in Structures for Hypersonic Flight, Pt. 2; p 577-599
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  • 50
    Publication Date: 2006-08-09
    Description: Based on the two dimensional theory of elasticity and by the use of Muskhelishvili's technique, the influence of a circular hole, under uniform normal pressure, on the stresses around a line crack in an infinite plate subjected to tension is discussed. Numerical calculations were carried out, and the variation of the crack tip stress intensity factor due to the geometry was clarified.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Advan. in Eng. Sci., Vol. 1; p 275-282
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  • 51
    Publication Date: 2006-07-02
    Description: Service problems encountered on the F-4 aircraft showed that the environmental qualification requirements for the UHF blade antenna were not adequate. Although the individual environmental levels were stringent enough, only combined environmental testing could duplicate the conditions in which service problems occurred. Techniques for applying static side load simultaneously with vibration and temperature were developed. The combined environment testing was instrumental in the rapid assessment of antenna modifications and resulted in a final configuration which proved satisfactory in service. A need to include combined environmental testing for qualification of blade antennas was established.
    Keywords: STRUCTURAL MECHANICS
    Type: Shock and Vibration Inform. Center The Shock and Vibration Bull., Pt. 3; p 79-84
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  • 52
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    In:  CASI
    Publication Date: 2004-10-30
    Description: Space shuttle liftoff dynamics
    Keywords: STRUCTURAL MECHANICS
    Type: SPACE TRANSPORTATION SYSTEM TECNOL. SYMP., VOL. 2 JUL. 1970; P 101-122
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  • 53
    Publication Date: 2006-03-28
    Description: Cybernetics diagnostics of machines and mechanisms using the spectral approach is discussed. The problem of establishing the accuracy of determination of the spectral composition is investigated. In systems with rectilinear or rotary movement, the vibrations appear in the form of movement rate vibrations, which are equivalent to frequency modulation of the signal, in proportion to the mean movement rate of the body. The case of a harmonic signal which reproduces and analyzes the characteristics of the frequency modulated signal is discussed. Mathematical models are developed to show the relationships of the parameters.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 275-278
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  • 54
    Publication Date: 2006-03-28
    Description: Free vibrations of a system and vibrations which are multiples of them in frequency are discussed. The corresponding periodic forced vibrations of the type n/m (n is the number of periods of disturbance between periods of movement and m is the number of periods of movement in one period of disturbance), generated by a harmonic or close to harmonic disturbance, are propagated close to the corresponding curves of the free vibrations and their frequency multiples. It has been proposed that investigation of transitional modes of motion and capture regions be carried out by precise methods in phase space, with the least number of coordinates. Thus, for example, for nonautonomous second order equations (for example, the Duffing equations), in place of three variables (coordinates, velocity, phases), it is proposed to use two: velocity during transition of the coordinate through zero and phase.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 256-259
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  • 55
    Publication Date: 2006-03-28
    Description: A numerical analysis of the transitional modes of motion for a vibroshock system was conducted. The capture regions of the system are emphasized. The three initial parameters for a nonautonomous vibroshock system with one degree of freedom are identified as: (1) coordinates, (2) velocity, and (3) time. Mathematical models are developed to show the relationship of the parameters. Graphs are included to show the nature of the capture regions and to portray the trajectory of motion of mass with time, by solution of differential equations during increase and decrease in time.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 250-255
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  • 56
    Publication Date: 2006-03-28
    Description: A solution is given to the problem of a transient vibration process in a fastened plate, during a sudden displacement of the edge. Some partial cases of excitation are examined in which the packing can be calculated and the explicit type of change in a deformation over time can be found. Some examples are presented.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 204-207
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  • 57
    Publication Date: 2006-03-28
    Description: The method of automatic identification of acoustical signals, by means of the segmentation was used to investigate noises and vibrations in machines and mechanisms, for cybernetic diagnostics. The structural analysis consists of presentation of a noise or vibroacoustical signal as a sequence of segments, determined by the time quantization, in which each segment is characterized by specific spectral characteristics. The structural spectrum is plotted as a histogram of the segments, also as a relation of the probability density of appearance of a segment to the segment type. It is assumed that the conditions of ergodic processes are maintained.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 179-180
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  • 58
    Publication Date: 2006-03-28
    Description: An experimental investigation for estimating the nonlinearity of a diagnostic object was carried out on a single-stage, spur gear reducer. The linearity of the properties of spur gearing (including the linearity of its mode of operation) was tested. Torsional vibrations of the driven wheel and transverse (to the meshing plane) vibrations of the drive wheel on its support were taken as the two outputs of the object to be analyzed. The results of the investigation showed that the degree of nonlinearity of a reducing gear is essentially connected with its operating mode, so that different mathematical models of it can correspond to different values of the system parameters.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 157-159
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  • 59
    Publication Date: 2006-03-01
    Description: The stability of equilibrium shapes of elastic systems is examined. Stability loss in the case of similar equilibrium shapes, the disappearance of stable equilibrium shapes, and the disappearance of any forms of equilibrium are discussed. The error made by Euler in analyzing stability loss is pointed out, and Mises' truss is used as an example of stability loss in the case of similar equilibrium shapes.
    Keywords: STRUCTURAL MECHANICS
    Type: Stability and Oscillation of Elastic Systems: Mod. Concepts, Paradoxes and Errors (NASA-TT-F-751); p 1-183
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  • 60
    facet.materialart.
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    In:  CASI
    Publication Date: 2006-03-01
    Description: Problems of oscillations of linear systems are discussed, including systems with a fractional number of degrees of freedom as well as free oscillations of a cantilever in the field of centrifugal forces. Four methods of solving the problem of the action of periodic instantaneous impulses are presented. The Tacoma catastrophe is analyzed and used as an example of aeroelastic oscillations. Problems of nonlinear system oscillations include the vibration maintenance of rotation, the Sommerfeld effect, and self-oscillations of a quasi-system with dry friction.
    Keywords: STRUCTURAL MECHANICS
    Type: Stability and Oscillation of Elastic Systems: Mod. Concepts, Paradoxes and Errors NASA-TT-F-751); p 184-418
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  • 61
    Publication Date: 2006-04-25
    Description: NASA computer program for dynamic structural analysis in stress and thermal deformation problems
    Keywords: STRUCTURAL MECHANICS
    Type: NIFICANT ACCOMPLISHMENTS IN SCI. AND TECHNOL. AT GODDARD SPACE FLIGHT CENTER 1970; P 221-224
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  • 62
    Publication Date: 2006-01-16
    Description: One type of azimuth bearing for a large ground antenna (100 m) will consist of steel wheels, mounted at four corners of the alidade, rolling on a circular flat rail which provides the vertical restraints; a radial constraining bearing at the center of the alidade provides the horizontal restraints. One important design feature is the compressive stresses in the grout or concrete foundation under the wheel-rail load. A finite element analysis check was made of a particular design that consists of a steel rail resting on a concrete foundation. Symmetry was assumed as much as possible in order to minimize the models, but meaningful element sizes were used. Recently developed isoparametric hexahedron elements available in the NASTRAN computing program, which minimizes the number of elements required while maintaining the accuracy of the computed stresses, were used with two versions of NASTRAN. Test cases to check with the analytical solutions were made. A side loading was also applied to calculate the increase in the concrete stresses.
    Keywords: STRUCTURAL MECHANICS
    Type: The Deep Space Network; p 204-215
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  • 63
    Publication Date: 2006-01-16
    Description: A simplified method called the transfer function technique (TFT) was devised for evaluating the stress wave environment in a structure containing internal equipment. The TFT consists of following the initial in-plane stress wave that propagates through a structure subjected to a dynamic load and characterizing how the wave is altered as it is transmitted through intersections of structural members. As a basis for evaluating the TFT, impact experiments and detailed stress wave analyses were performed for structures with two or three, or more members. Transfer functions that relate the wave transmitted through an intersection to the incident wave were deduced from the predicted wave response. By sequentially applying these transfer functions to a structure with several intersections, it was found that the environment produced by the initial stress wave propagating through the structure can be approximated well. The TFT can be used as a design tool or as an analytical tool to determine whether a more detailed wave analysis is warranted.
    Keywords: STRUCTURAL MECHANICS
    Type: Shock and Vibration Inform. Center The Shock and Vibration Bull., Pt. 1; p 89-96
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  • 64
    Publication Date: 2006-01-16
    Description: A technique for simulating high g level pyrotechnic shocks is described and the results of applying the technique to obtain the MIL-STD-1540A shock spectrum with a maximum acceleration of 18,000g at 2,000 Hz are presented. Designing the resonant beam and plate on which the test unit is mounted, and generating a proper impulsive load on them, were the essentials of the technique. One dimensional stress wave and Euler equations were employed in the design. A metal pendulum hammer was used to generate the impulsive load.
    Keywords: STRUCTURAL MECHANICS
    Type: Shock and Vibration Inform. Center The Shock and Vibration Bull., Pt. 1; p 97-100
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  • 65
    Publication Date: 2006-01-16
    Description: A previously proposed cumulative fatigue damage law is extended to predict the probability of failure or fatigue life for structural materials with S-N fatigue curves represented as a scatterband of failure points. The proposed law applies to structures subjected to sinusoidal or random stresses and includes the effect of initial crack (i.e., flaw) sizes. The corrected cycle ratio damage function is shown to have physical significance.
    Keywords: STRUCTURAL MECHANICS
    Type: Shock and Vibration Inform. Center The Shock and Vibration Bull., Pt. 1; p 31-41
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  • 66
    Publication Date: 2006-01-11
    Description: One of the most important methods of reducing the noise and vibration level is the damping of the secondary sources, such as metal plates, often used in vehicle structures, by means of covering materials with high internal viscosity. Damping layers are chosen at an optimum thickness corresponding to the frequency and temperature range in which a certain structure works. The structure's response corresponding to various real situations is analyzed by means of a measuring chain including electroacoustical or electromechanical transducers. The experimental results provide the dependence of the loss factor and damping transmission coefficient as a function of the damping layer thickness or of the frequency for various viscoelastic covering materials.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 246-253
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  • 67
    Publication Date: 2006-01-11
    Description: Vibration sources are described for pneumatic hammers used in the mining industry (pick hammers), in boiler shops (riveting hammers), etc., bringing to light the fact that the principal vibration source is the variation in air pressure inside the cylinder. The present state of the art of vibration control of pneumatic hammers as it is practiced abroad, and the solutions adopted for this purpose, are discussed. A new type of pneumatic hammer with a low noise and vibration level is presented.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 79-84
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  • 68
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    In:  CASI
    Publication Date: 2006-01-11
    Description: Special measures are discussed for calculating, designing and executing a forge hammer foundation, so that the vibrations that occur during its working will not be transmitted to neighboring machinery, workrooms and offices. These vibrations are harmful to the workers near the forge hammer.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 73-78
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  • 69
    Publication Date: 2006-01-11
    Description: Because of the high vibration level occurring during the running of electric locomotives, mechanical defects occur in the control mechanisms of auxiliary services. This fact has given rise to the necessity of determining the values of these vibrations in electric locomotives during their running. Measurements were conducted on the Craiova-Drobeta-Turnu Severin line, and measures to reduce the vibration level in electric locomotives were instituted.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 50-54
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  • 70
    Publication Date: 2006-01-11
    Description: A method is presented of determining the mean square transversal deflection of an isotropic and homogeneous linear viscoelastic beam having a certain number of lengthwise distributed lumped masses. It is assumed that the beam is acted upon by a stationary random process uniformly distributed along the beam. The method is useful in vibration level control by means of additional lumped masses.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 36-42
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  • 71
    facet.materialart.
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    In:  CASI
    Publication Date: 2006-01-11
    Description: An oscillating system with quadratic damping subjected to white noise excitation is replaced by a nonlinear, statistically equivalent system for which the associated Fokker-Planck equation can be exactly solved. The mean square responses are calculated and the optimum damping coefficient is determined with respect to the minimum mean square acceleration criteria. An application of these results to the optimization of automobile suspension damping is given.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 29-35
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  • 72
    Publication Date: 2006-01-11
    Description: A seismic action which is characterized by the acceleration function of the seismic motion is analyzed. The equations of motion in the direction of the seismic action are determined for a completely rigid ground and for a ground with linear deformability characteristics (rotation deformability). The equation for the rotation motion is derived by considering elastic and viscoelastic properties of the foundation ground. The differential equations are written by treating the mechanical model of a many-storied structure as a fixed vertical beam with a uniformly distributed mass as well as with concentrated masses on each floor.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 43-49
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  • 73
    Publication Date: 2006-01-11
    Description: The insulation of nonlinear and random vibrations is considered for some ore preparing and sorting implements: rotary crushers, resonance screens, hammer mills, etc. The appearance of subharmonic vibrations is analyzed, and the conditions for their appearance are determined. A method is given for calculating the insulation of these vibrations by means of elastic elements made of rubber. The insulation of the random vibrations produced by Symons crushers is calculated by determining the transmissability and deformation of the insulation system for a narrow band random response.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 22-28
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  • 74
    Publication Date: 2006-01-11
    Description: Expressions are derived for the displacements of a many storied building subjected to the action of classical weaving looms located at different levels of the building. The building is regarded as a vertical fixed beam with a uniformly distributed mass as well as concentrated masses at each level. The calculation relations are obtained on the assumption of harmonic variation of the forces acting at each level as well as the assumption of narrow band stationary random excitatory forces.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 15-21
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  • 75
    Publication Date: 2006-01-11
    Description: For compacting concretes in building, vibrating beams are used. The vibrations are generated by inertial vibrators, and the beam is normally displaced by the operator by means of a handle that is elastically fastened to the beam by means of rubber pads. Considered are vibrations transmitted to the operator, taking into account the beam's shock vibration motions. The steady state motion of a dynamic beam pattern is studied, and results of experimental tests with existing equipment are presented.
    Keywords: STRUCTURAL MECHANICS
    Type: The 4th Natl. Conf. on Acoustics, Vol. 1A (NASA-TT-F-15375); p 9-14
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  • 76
    Publication Date: 2006-04-02
    Description: Asymptotic solutions of Novozhilov's equations of shells of revolution are derived for axisymmetric and first harmonic loadings. The solutions obtained are valid throughout the shallow and nonshallow regions. Stresses in dome shaped shells of revolution with a discontinuity in the form of a circular hole, a circular rigid insert, or a nozzle at the apex have been investigated. Numerical results are obtained for spheres, ellipsoids, and paraboloids, containing a discontinuity under a internal pressure and moment. Curves depicting stress distributions are given. The influence of three types of discontinuity on the stresses of the shells is also given.
    Keywords: STRUCTURAL MECHANICS
    Type: Multivariant Function Model Generation; 118 p
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  • 77
    Publication Date: 2006-03-28
    Description: The problem is discussed of identification of a linear object of known structure, the movement of which is described by a system of differential equations of the type y = Ay + Bu, where y is an n-dimensional output vector, u is an m-dimensional vector of stationary, random disturbances (inputs), A and B are matrices of unknown parameters of the dimension, n x n and n x m, respectively. The spectral and reciprocal spectral densities of the inputs and outputs are used as the initial information on the object.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 139-141
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  • 78
    Publication Date: 2006-03-28
    Description: Radial and axial vibration measurements on the scanning disk and the data storage board of an optical-mechanical scanner are evaluated. Statistical processing of the observational data establishes the excitation source and determines the effect of disk torsional vibrations on the data storage board.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 105-106
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  • 79
    Publication Date: 2006-03-28
    Description: The torque of a drive shaft in a magnetic recording device was studied by oscillographic recordings. Statistical evaluation of the dynamic spectral densities showed that the principle source of disturbing forces is loading in the drive shaft radial play.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 103-104
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  • 80
    Publication Date: 2006-03-28
    Description: The equation of motion was used to examine the problem of vibrations of a thin elastic plate covered with a thin viscous layer. Mathematical formulation and the solution of the problem are given.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 89-90
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  • 81
    Publication Date: 2006-03-28
    Description: The statistical characteristics of complex variation amplitudes of shells excited by harmonic force sources in the sound frequency range are examined. Vibrations were measured with a multichannel unit, permitting the component values of a complex vibration amplitude for the i-th measurement point to be obtained at each measured point. An estimation was also made of the nature of the vibration field structure.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 68-73
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  • 82
    Publication Date: 2006-03-28
    Description: A traveling wave unit was built to process measurement data on spatial damping parameters and to simplify statistical treatment of the results. Mean values of the loss coefficient, lengths of flexual waves, and wave propagation velocities for a given set of discrete functions were determined. Results are given in a table.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 81-82
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  • 83
    Publication Date: 2006-03-28
    Description: A method is proposed for determining vibroacoustic characteristics from the results of measurements of the distribution of vibrational energy in a structure. The method is based on an energy model of a structure studied earlier. Equations are written to describe the distribution of vibrational energy in a hypothetical diffuse energy state in structural elements.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 74-77
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  • 84
    Publication Date: 2006-03-28
    Description: The distribution pattern of the amplitudes of vibrations, measured at various points on the surface of a shell, stimulated by a point source of harmonic force in the sound frequency range was studied experimentally. This pattern permits a valid spacing estimate to be carried out of the average structural characteristics of the vibrations, which are used for both estimation of the vibration excitability of the structure and for estimation of the effectiveness of use of a vibration-absorbing covering.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 61-67
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  • 85
    Publication Date: 2006-03-28
    Description: A method, developed for making measurements in reverberation chambers in the steady state mode, is reported. Spatial distribution patterns of the square of the sound pressure vs type of exciting signal were produced theoretically and checked experimentally in a reverberation chamber. Results of measurements of spatial irregularities of the field with pure tones and with noise bands in the 200 to 2,000 Hz frequency range were used for calculating statistical parameters of the reverbation fields by computer. The calculation program included determination of density probability function, integral distribution pattern, mathematical expectation, normalized dispersion of the mean square of the pressure.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 57-60
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  • 86
    Publication Date: 2006-03-28
    Description: Research was begun into the dynamic characteristics of wires, including the self-damping properties. A series of wire insulator fastenings, with and without dampers, was also developed.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 48-49
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  • 87
    Publication Date: 2006-03-28
    Description: Various calculation schemes were proposed for describing vibrations in a piping system with pulsating flow. Methods were selected and applied according to the type of irregularities examined: concentrated ones, extended ones, or complex ones. The selection of a method also depends on comparability of the extent of the irregularities with the pressure wavelength and velocity in the flow. Relations were found which permit a description of the interaction of a pulsating flow with any irregularity in the system. For complex systems with varying temperatures and some irregularities, relations were obtained, which reflect the varying phase displacement of the forces in these irregularities. The effect of the frictional torque on pipeline supports, in the presence of flexural and torsional vibrations was investigated, on the assumption that the frictional torque depends linearly on the angular velocity.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 51-52
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  • 88
    Publication Date: 2006-03-28
    Description: Certain characteristics of the reactions of typical skin panels of a passenger aircraft to acoustical loading are being investigated, for development of an objective method of diagnostics for skin condition, under the operations and maintenance sections of civil aviation. There are a number of difficulties connected with the solution of this problem. The reactions of skin panels exposed to the noises of the exhaust jets are dependent on the aircraft operating conditions, the geometric parameters and limiting conditions of the panels.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 41-43
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  • 89
    Publication Date: 2006-03-28
    Description: A program was compiled for calculating acoustical pressure levels, which might be created by vibrations of complex structures (an assembly of shells and rods), under the influence of a given force, for cases when these fields cannot be measured directly. The acoustical field is determined according to transition frequency and pulse characteristics of the structure in the projection mode. Projection characteristics are equal to the reception characteristics, for vibrating systems in which the reciprocity principle holds true. Characteristics in the receiving mode are calculated on the basis of experimental data on a point pulse space velocity source (input signal) and vibration response of the structure (output signal). The space velocity of a pulse source, set at a point in space r, where it is necessary to calculate the sound field of the structure p(r,t), is determined by measurements of acoustic pressure, created by a point source at a distance R. The vibration response is measured at the point where the forces F and f exciting the system should act.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 53-56
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  • 90
    Publication Date: 2006-03-28
    Description: Endless structures are realized in practice, in the presence of loss and to an adequate extent, owing to which, reflections from the edges to the center part of the structure can be disregarded. In the absence of losses, reflections from the boundary frequently have to be taken into account. In this case, besides compensation for waves passing through the boundary, the reciprocal connection system can be used for compensation of the total field ahead of the boundary. In these cases, the system converters can be located in a different manner relative to the boundary and to one another. Each of the locations has inherent peculiarities, which must be taken into account in solving specific problems.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 222-228
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  • 91
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    In:  CASI
    Publication Date: 2006-03-28
    Description: The vibration characteristics of an unidimensional structure are discussed. The cases considered are: (1) a rigid pipe in which a wave propagates, (2) an infinite string along which a transverse wave propagates, (3) a rod along which longitudinal or torsional columns propagate, and (4) generally a unidimensional propagation of some one mode of vibrations which is nondegenerating with distance. Mathematical models are developed to show the performance of the mechanical devices under various damping conditions.
    Keywords: STRUCTURAL MECHANICS
    Type: Cybernetic Diagnostics of Mech. Systems with Vibro-acoustic Phenomena (NASA-TT-F-14899); p 216-221
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  • 92
    Publication Date: 2006-08-09
    Description: The effect of subcritical crack growth on the geometry dependence of nonlinear fracture toughness parameters was studied by comparing the toughness values for different specimen geometries at the onset of subcritical crack growth and at the initiation of unstable crack propagation. Center-cracked thin sheet specimens of 2024-T3 and 7075-T6 aluminum alloys were tested by varying the specimen length L, width w, and crack length-to-width ratio c/w. When the onset of unstable crack propagation was selected as the critical point, the nonlinear energy toughness and the R curve toughness increased with increasing w and decreasing L and c/w. However, when the onset of subcritical crack growth was taken as the critical point, energy toughness and the linear toughness values were independent of these geometrical variables.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Advan. in Eng. Sci., Vol. 1; p 257-266
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  • 93
    Publication Date: 2006-08-09
    Description: The problem to be considered is the sudden appearance of a flaw or crack in a strip of material of finite height subjected to tensile loading. Stress waves are generated within the strip and are reflected from boundary to boundary. Of interest is the maximum value of the dynamic stress intensity factor at a given instance of time as the strip height to crack length ratio is varied.
    Keywords: STRUCTURAL MECHANICS
    Type: NASA. Langley Res. Center Advan. in Eng. Sci., Vol. 1; p 205-214
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  • 94
    Publication Date: 2011-10-14
    Description: As the performance of aerospace vehicles has increased, the noise generated by the propulsion system and by the passage of the vehicle through the air has also increased. Further increases in performance are now underway for space vehicles such as the space shuttle vehicle and for short distance takeoff and landing (STOL) aircraft, and are being planned for supersonic aircraft. The flight profiles and design features of these high-performance vehicles are reviewed and an estimate made of selected noise-induced structural vibration problems. Considerations for the prevention of acoustic fatigue, noise transmission, and electronic instrument malfunction are discussed.
    Keywords: STRUCTURAL MECHANICS
    Type: AGARD Noise Mech.; 16 p
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  • 95
    Publication Date: 2011-08-16
    Description: Elastic harmonic waves propagation in composite circular elastic cylinder
    Keywords: STRUCTURAL MECHANICS
    Type: ; VUE SCIENTIFIQUE ET
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  • 96
    Publication Date: 2011-08-16
    Description: Bond rupture and fracture in semicrystalline polymers, noting agreement with random length molecular tie chain scission model
    Keywords: STRUCTURAL MECHANICS
    Type: ; TROPHYSICAL JOURNAL
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  • 97
    Publication Date: 2011-08-16
    Description: Optimum design for buckling prevention in cylindrical shells under lateral pressure
    Keywords: STRUCTURAL MECHANICS
    Type: BL. IN STRESS ANALYSIS AND OPTIMUM DESIGN FEB. 1970 (SEE N71-24642 13-32) 13-32/
    Format: text
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  • 98
    Publication Date: 2011-08-16
    Description: Stress analysis of unidirectionally reinforced, composite plates with holes
    Keywords: STRUCTURAL MECHANICS
    Type: BL. IN STRESS ANALYSIS AND OPTIMUM DESIGN FEB. 1970 (SEE N71-24642 13-32) 13-32/
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  • 99
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: The nature of aerospace noise-induced vibration problems is summarized, with emphasis placed on reviewing and categorizing types and sources of noise which are significant in such problems. Physical characteristics of representative noise loads associated with propellers, turbojet engine exhausts, and sonic boom waves are presented. Examples of noise-induced structural vibrations are discussed.
    Keywords: STRUCTURAL MECHANICS
    Type: Sound and Vibration; 5; Dec. 197
    Format: text
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  • 100
    Publication Date: 2011-08-16
    Description: Collection of theoretical and experimental studies covering basic mechanisms of fatigue in the subcreep and creep ranges, fatigue damage detection, field practices for fatigue damage repair in jet engine components, and fatigue damage avoidance and control. Individual items are abstracted in this issue.
    Keywords: STRUCTURAL MECHANICS
    Format: text
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