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  1. LOADING TESTS OF A WING STRUCTURE FOR A HYPERSONIC AIRCRAFT , Technical Paper
    Authors: R. A. Fields, L. F. Reardon and W. H. Siegel
    Report Number: NASA-TP-1596
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Room-temperature loading tests were conducted on a wing structure designed with a beaded panel concept for a Mach 8 hypersonic research airplane. Strain, stress, and deflection data were compared with the results of three finite-element structural analysis computer programs and with design data. The test program data were used to evaluate the structural concept and the methods of analysis used in the design. A force stiffness technique was utilized in conjunction with load conditions which produced various combinations of panel shear and compression loading to determine the failure envelope of the buckling critical beaded panels The force-stiffness data did not result in any predictions of buckling failure. It was, therefore, concluded that the panels were conservatively designed as a result of design constraints and assumptions of panel eccentricities. The analysis programs calculated strains and stresses competently. Comparisons between calculated and measured structural deflections showed good agreement. The test program offered a positive demonstration of the beaded panel concept subjected to room-temperature load conditions.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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    Report Date: January 1980
    No. Pages: 72
    Keywords:      Hypersonic aircraft; Load tests; Spot welds; Stress-strain diagrams; Wing panels.


  2. LANDING APPROACH AIRFRAME NOISE MEASUREMENTS AND ANALYSIS , Technical Paper
    Authors: P. L. Lasagna, K. G. Mackall, F. W. Burcham, Jr. and T. W. Putnam
    Report Number: NASA-TP-1602
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flyover measurements of the airframe noise produced by the AeroCommander, JetStar, CV-990, and B-747 airplanes are presented for various landing approach configurations. Empirical and semiempirical techniques are presented to correlate the measured airframe noise with airplane design and aerodynamic parameters. Airframe noise for the jet-powered airplanes in the clean configuration (flaps and gear retracted) was found to be adequately represented by a function of airplane weight and the fifth power of airspeed. Results show the airframe noise for all four aircraft in the landing configuration (flaps extended and gear down) also varied with the fifth power of airspeed, but this noise level could not be represented by the addition of a constant to the equation for clean-configuration airframe noise.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 01
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    Report Date: January 1980
    No. Pages: 36
    Keywords:      Aircraft landing; Aircraft noise; Airframes; Approach; Noise measurement.


  3. WIND-TUNNEL/FLIGHT CORRELATION STUDY OF AERODYNAMIC CHARACTERISTICS OF A LARGE FLEXIBLE SUPERSONIC CRUISE AIRPLANE (XB-70-1). 3: A COMPARISON BETWEEN CHARACTERISTICS PREDICTED FROM WIND-TUNNEL MEASUREMENTS AND THOSE MEASURED IN FLIGHT , Technical Paper
    Authors: H. H. Arnaiz, J. B. Peterson, Jr. and J. C. Daugherty
    Report Number: NASA-TP-1516
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A program was undertaken by NASA to evaluate the accuracy of a method for predicting the aerodynamic characteristics of large supersonic cruise airplanes. This program compared predicted and flight-measured lift, drag, angle of attack, and control surface deflection for the XB-70-1 airplane for 14 flight conditions with a Mach number range from 0.76 to 2.56. The predictions were derived from the wind-tunnel test data of a 0.03-scale model of the XB-70-1 airplane fabricated to represent the aeroelastically deformed shape at a 2.5 Mach number cruise condition. Corrections for shape variations at the other Mach numbers were included in the prediction. For most cases, differences between predicted and measured values were within the accuracy of the comparison. However, there were significant differences at transonic Mach numbers. At a Mach number of 1.06 differences were as large as 27 percent in the drag coefficients and 20 deg in the elevator deflections. A brief analysis indicated that a significant part of the difference between drag coefficients was due to the incorrect prediction of the control surface deflection required to trim the airplane.
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    Subject Category: 02
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    Report Date: March 1980
    No. Pages: 59
    Keywords:      Aerodynamic characteristics; B-70 aircraft; Data correlation; Flight tests; Wind tunnel tests.


  4. USER'S MANUAL FOR MMLE3, A GENERAL FORTRAN PROGRAM FOR MAXIMUM LIKELIHOOD PARAMETER ESTIMATION , Technical Paper
    Authors: R. E. Maine and K. W. Iliff
    Report Number: NASA-TP-1563
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A user's manual for the FORTRAN IV computer program MMLE3 is described. It is a maximum likelihood parameter estimation program capable of handling general bilinear dynamic equations of arbitrary order with measurement noise and/or state noise (process noise). The theory and use of the program is described. The basic MMLE3 program is quite general and, therefore, applicable to a wide variety of problems. The basic program can interact with a set of user written problem specific routines to simplify the use of the program on specific systems. A set of user routines for the aircraft stability and control derivative estimation problem is provided with the program.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 59
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    Report Date: November 1980
    No. Pages: 90
    Keywords:      Computer programs; Flight tests; FORTRAN; Maximum likelihood estimates; Parameter identification.


  5. WIND TUNNEL INVESTIGATION OF AN ALL FLUSH ORIFICE AIR DATA SYSTEM FOR A LARGE SUBSONIC AIRCRAFT , Technical Paper
    Authors: T. J. Larson, S. G. Flechner and P. M. Siemers III
    Report Number: NASA-TP-1642
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The results of a wind tunnel investigation on an all flush orifice air data system for use on a KC-135A aircraft are presented. The investigation was performed to determine the applicability of fixed all flush orifice air data systems that use only aircraft surfaces for orifices on the nose of the model (in a configuration similar to that of the shuttle entry air data system) provided the measurements required for the determination of stagnation pressure, angle of attack, and angle of sideslip. For the measurement of static pressure, additional flush orifices in positions on the sides of the fuselage corresponding to those in a standard pitot-static system were required. An acceptable but less accurate system, consisting of orifices only on the nose of the model, is defined and discussed.
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    Report Date: May 1980
    No. Pages: 97
    Keywords:      Air data systems; C-135 aircraft; Data acquisition; Orifices; Pressure measurement.


  6. PRECISION CONTROLLABILITY OF THE YF-17 AIRPLANE , Technical Paper
    Authors: T. R. Sisk and N. W. Matheny
    Report Number: NASA-TP-1677
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A flying qualities evaluation conducted on the YF-17 airplane permitted assessment of its precision controllability in the transonic flight regime over the allowable angle of attack range. The precision controllability (tailchase tracking) study was conducted in constant-g and windup turn tracking maneuvers with the command augmentation system (CAS) on, automatic maneuver flaps, and the caged pipper gunsight depressed 70 mils. This study showed that the YF-17 airplane tracks essentially as well at 7 g's to 8 g's as earlier fighters did at 4 g's to 5 g's before they encountered wing rock. The pilots considered the YF-17 airplane one of the best tracking airplanes they had flown. Wing rock at the higher angles of attack degraded tracking precision, and lack of control harmony made precision controllability more difficult. The revised automatic maneuver flap schedule incorporated in the airplane at the time of the tests did not appear to be optimum. The largest tracking errors and greatest pilot workload occurred at high normal load factors at low angles of attack. The pilots reported that the high-g maneuvers caused some tunnel vision and that they found it difficult to think clearly after repeated maneuvers.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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    Report Date: May 1980
    No. Pages: 34
    Keywords:      Controllability; F-17 aircraft; Maneuverability; Pilot performance; Tracking (position).


  7. DEVELOPMENT AND FLIGHT TEST RESULTS OF AN AUTOTHROTTLE CONTROL SYSTEM AT MACH 3 CRUISE , Technical Paper
    Authors: G. B. Gilyard and J. J. Burken
    Report Number: NASA-TP-1621
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flight test results obtained with the original Mach hold autopilot designed the YF-12C airplane which uses elevator control and a newly developed Mach hold system having an autothrottle integrated with an altitude hold autopilot system are presented. The autothrottle tests demonstrate good speed control at high Mach numbers and high altitudes while simultaneously maintaining control over altitude and good ride qualities. The autothrottle system was designed to control either Mach number or knots equivalent airspeed (KEAS). Excellent control of Mach number or KEAS was obtained with the autothrottle system when combined with altitude hold. Ride qualities were significantly better than with the conventional Mach hold system.
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    Report Date: July 1980
    No. Pages: 40
    Keywords:      Airspeed; Automatic Pilots; Flight Control; Flight Tests; Mach Number; YF-14 Aircraft; Flight Simulation; Kinetic Energy; Potiential Energy; Supersonic Speed


  8. STRUCTURAL PROPERTIES OF SUPERPLASTICALLY FORMED/DIFFUSION-BONDED ORTHOGONALLY CORRUGATED CORE SANDWICH PLATES , Conference Paper
    Authors: W. L. Ko
    Report Number: H-1091
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: This paper describes a new superplastically formed/diffusion-bonded (SPF/DB) orthogonally corrugated sandwich structure, and presents formulae and the associated plots for evaluating the effective elastic constants for the core of this new sandwich structure. Comparison of structural properties of this new sandwich structure with the conventional honeycomb core sandwich structure was made under the condition of equal sandwich density. It was found that the SPF/DB orthogonally corrugated sandwich core has higher transverse shear stiffness than the conventional honeycomb sandwich core. However, the former has lower stiffness in the sandwich core thickness direction than the latter.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 39
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    Report Date: January 1980
    No. Pages: 15
    Keywords:      Corrugated plates; Diffusion welding; Honeycomb cores; Sandwich structures; Superplasticity.
    Notes: American Institute of Aeronautics and Astronautics, Aerospace Sciences Meeting, 18th, Pasadena, Calif., Jan. 14-16, 1980.


  9. ELASTIC CONSTANTS FOR SUPERPLASTICALLY FORMED/DIFFUSION-BONDED CORRUGATED SANDWICH CORE , Technical Paper
    Authors: W. L. Ko
    Report Number: NASA-TP-1562
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Formulas and associated graphs for evaluating the effective elastic constants for a superplastically formed/diffusion bonded (SPF/DB) corrugated sandwich core, are presented. A comparison of structural stiffnesses of the sandwich core and a honeycomb core under conditions of equal sandwich core density was made. The stiffness in the thickness direction of the optimum SPF/DB corrugated core (that is, triangular truss core) is lower than that of the honeycomb core, and that the former has higher transverse shear stiffness than the latter.
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    Subject Category: 39
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    Report Date: May 1980
    No. Pages: 83
    Keywords:      Diffusion welding; Elastic properties; Sandwich structures; Structural stability; Superplasticity.


  10. USE OF NOSE CAP AND FUSELAGE PRESSURE ORIFICES FOR DETERMINATION OF AIR DATA FOR SPACE SHUTTLE ORBITER BELOW SUPERSONIC SPEEDS , Technical Paper
    Authors: T. J. Larson and P. M. Siemers, III
    Report Number: NASA-TP-1643
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Wind tunnel pressure measurements were acquired from orifices on a 0.1 scale forebody model of the space shuttle orbiter that were arranged in a preliminary configuration of the shuttle entry air data system (SEADS). Pressures from those and auxiliary orifices were evaluated for their ability to provide air data at subsonic and transonic speeds. The orifices were on the vehicle's nose cap and on the sides of the forebody forward of the cabin. The investigation covered a Mach number range of 0.25 to 1.40 and an angle of attack range from 4 deg. to 18 deg. An air data system consisting of nose cap and forebody fuselage orifices constitutes a complete and accurate air data system at subsonic and transonic speeds. For Mach numbers less than 0.80 orifices confined to the nose cap can be used as a complete and accurate air data system. Air data systems that use only flush pressure orifices can be used to determine basic air data on other aircraft at subsonic and transonic speeds.
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    Subject Category: 06
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    Report Date: September 1980
    No. Pages: 128
    Keywords:      Orifice flow; Pressure gradients; Space shuttle orbiters; Subsonic speed: Transonic speed.


  11. IN-FLIGHT BOUNDARY-LAYER MEASUREMENTS ON A HOLLOW CYLINDER AT A MACH NUMBER OF 3.0 , Technical Paper
    Authors: R. D. Quinn and L. Gong
    Report Number: NASA-TP-1764
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Skin temperatures, shear forces, surface static pressures, boundary layer pitot pressures, and boundary layer total temperatures were measured on the external surface of a hollow cylinder that was 3.04 meters long and 0.437 meter in diameter and was mounted beneath the fuselage of the YF-12A airplane. The data were obtained at a nominal free stream Mach number of 3.0 (a local Mach number of 2.9) and at wall to recovery temperature ratios of 0.66 to 0.91. The local Reynolds number had a nominal value of 4,300,000 per meter. Heat transfer coefficients and skin friction coefficients were derived from skin temperature time histories and shear force measurements, respectively. In addition, boundary layer velocity profiles were derived from pitot pressure measurements, and a Reynolds analogy factor was obtained from the heat transfer and skin friction measurements. The measured data are compared with several boundary layer prediction methods.
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    Report Date: November 1980
    No. Pages: 52
    Keywords:      Cylindrical bodies; Heat transfer coefficients; Mach number; Static pressure.


  12. ESTIMATION OF THE ACCURACY OF DYNAMIC FLIGHT-DETERMINED COEFFICIENTS , Conference Paper
    Authors: R. E. Maine and K. W. Iliff
    Report Number: H-1107
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: This paper discusses means of assessing the accuracy of maximum likelihood parameter estimates obtained from dynamic flight data. The commonly used analytical predictors of accuracy are compared from both statistical and simplified geometric standpoints. Emphasizing practical considerations, such as modeling error, the accuracy predictions are evaluated with real and simulated data. Improved computations of the Cramer-Rao bound to correct large discrepancies caused by colored noise and modeling error are presented. This corrected Cramer-Rao bound is the best available analytical predictor of accuracy. Engineering judgement, aided by such analytical tools, is the final arbiter of accuracy estimation.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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    Report Date: January 1980
    No. Pages: 18
    Keywords:      Aerodynamic coefficients; Aircraft control; Aircraft stability; Flight tests; Stability derivatives.
    Notes: American Institute of Aeronautics and Astronautics, Aerospace Sciences Meeting, 18th, Pasadena, Calif., Jan. 14-16, 1980.


  13. A MODIFIED T-VALUE METHOD FOR SELECTION OF STRAIN GAGES FOR MEASURING LOADS ON A LOW ASPECT RATIO WING , Technical Paper
    Authors: M. H. Tang and R. G. Sheldon
    Report Number: NASA-TP-1748
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A technique which may be useful for selecting strain gages for use in load equations is described. The technique is an adaptation of the previously used T-value method and is applied to a multispar structure. The technique, called the modified T-value method, is used to reduce the number of strain gages used in a load equation from twelve to two. A parallel reduction is made by calculating relative equation accuracies from three applied load distributions. The equations developed from the modified T-value method proved to be accurate more consistently than the T-value method.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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    Report Date: November 1980
    No. Pages: 54
    Keywords:      Graphs (charts); Load distribution (forces); Regression coefficients; Strain gages; Tables (data).


  14. FLIGHT-MEASURED EFFECTS OF BOATTAIL ANGLE AND MACH NUMBER ON THE NOZZLE AFTERBODY FLOW OF A TWIN-JET FIGHTER , Conference Paper
    Authors: T. J. Plant, J. Nugent and R. A. Davis
    Report Number: H-1110
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The paper presents the flight-measured nozzle afterbody surface pressures and engine exhaust nozzle pressure-area integrated axial force coefficients on a twin-jet fighter for varying boattail angles. The objective of the tests was to contribute to a full-scale flight data base applicable to the nozzle afterbody drag of advanced tactical fighter concepts. The data were acquired during the NASA F-15 Propulsion/Airframe Interactions Flight Research Program. Nozzle boattail angles from 7.7 deg to 18.1 deg were investigated. Results are presented for cruise angle of attack at Mach numbers from 0.6 to 2.0 at altitudes from 20,000 to 45,000 feet. The data show the nozle axial force coefficients to be a strong function of nozzle boattail angle and Mach number.
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    Subject Category: 02
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    Report Date: January 1980
    No. Pages: 13
    Keywords:      Afterbodies; Boattails; F-15 aircraft; Flight tests; Flow geometry.
    Notes: American Institute of Aeronautics and Astronautics, Aerospace Sciences Meeting, 18th, Pasadena, Calif., Jan. 14-16, 1980.


  15. ELASTIC STABILITY OF SUPERPLASTICALLY FORMED/DIFFUSION-BONDED ORTHOGONALLY CORRUGATED CORE SANDWICH PLATES , Conference Paper
    Authors: W. L. Ko
    Report Number: H-1112
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The paper concerns the elastic buckling behavior of a newly developed superplastically formed/diffusion-bonded (SPF/DB) orthogonally corrugated core sandwich plate. Uniaxial buckling loads were calculated for this type of sandwich plate with simply supported edges by using orthotropic sandwich plate theory. The buckling behavior of this sandwich plate was then compared with that of an SPF/DB unidirectionally corrugated core sandwich plate under conditions of equal structural density. It was found that the buckling load for the former was considerably higher than that of the latter.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 39
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    Report Date: January 1980
    No. Pages: 10
    Keywords:      Corrugated plates; Elastic buckling; Elastic plates; Sandwich structures; Structural stability.
    Notes: In: Structures, Structural Dynamics, and Materials Conference, 21st, Seattle, Wash., May 12-14, 1980, Technical Papers. Part 1.


  16. DESIGN OF A NONLINEAR ADAPTIVE FILTER FOR SUPPRESSION OF SHUTTLE PILOT-INDUCED OSCILLATION TENDENCIES , Technical Memorandum
    Authors: J. W. Smith and J. W. Edwards
    Report Number: NASA-TM-81349
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Analysis of a longitudinal pilot-induced oscillation (PIO) experienced just prior to touchdown on the final flight of the space shuttle's approach landing tests indicated that the source of the problem was a combination of poor basic handling qualities aggravated by time delays through the digital flight control computer and rate limiting of the elevator actuators due to high pilot gain. A nonlinear PIO suppression (PIOS) filter was designed and developed to alleviate the vehicle's PIO tendencies by reducing the gain in the command path. From analytical and simulator studies it was shown that the PIOS filter, in an adaptive fashion, can attenuate the command path gain without adding phase lag to the system. With the pitch attitude loop of a simulated shuttle model closed, the PIOS filter increased the gain margin by a factor of about two.
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    Subject Category: 08
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    Report Date: April 1980
    No. Pages: 31
    Keywords:      Adaptive filters; Controllability; Digital simulation; Flight control; Longitudinal control.


  17. BIVARIATE NORMAL, CONDITIONAL AND RECTANGULAR PROBABILITIES: A COMPUTER PROGRAM WITH APPLICATIONS , Technical Memorandum
    Authors: R. Swaroop, J. D. Brownlow, G. R. Ashworth and W. R. Winter
    Report Number: NASA-TM-81350
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Some results for the bivariate normal distribution analysis are presented. Computer programs for conditional normal probabilities, marginal probabilities, as well as joint probabilities for rectangular regions are given: routines for computing fractile points and distribution functions are also presented. Some examples from a closed circuit television experiment are included.
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    Subject Category: 65
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    Report Date: May 1980
    No. Pages: 39
    Keywords:      Bivariate analysis; Computer programs; Probability distribution functions.


  18. SUBSONIC TESTS OF AN ALL-FLUSH-PRESSURE-ORIFICE AIR DATA SYSTEM , Technical Paper
    Authors: T. J. Larson and P. M. Siemers, III
    Report Number: NASA-TP-1871
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The use of an all-flush-pressure-orifice array as a subsonic air data system was evaluated in flight and wind tunnel tests. Two orifice configurations were investigated. Both used orifices arranged in a cruciform pattern on the airplane nose. One configuration also used orifices on the sides of the fuselage for a source of static pressure. The all-nose-orifice configuration was similar to the shuttle entry air data system (SEADS). The flight data were obtained with a KC-135A airplane. The wind tunnel data were acquired with a 0.035-scale model of the KC-135A airplane. With proper calibration, several orifices on the vertical centerline of the vehicle's nose were found to be satisfactory for the determination of total pressure and angle of attack. Angle of sideslip could be accurately determined from pressure measurements made on the horizontal centerline of the aircraft. Orifice pairs were also found that provided pressure ratio relationships suitable for the determination of Mach number. The accuracy that can be expected for the air data determined with SEADS during subsonic orbiter flight is indicated.
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    Subject Category: 06
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    Report Date: June 1980
    No. Pages: 50
    Keywords:      Air data systems; Airspeed; Flight tests; Orifices; Pressure distribution.
    Notes: Presented at the 1980 Air Data Systems Conf., Colorado Springs, Colo., May 1980.


  19. CALCULATION OF THE TRANSIENT MOTION OF ELASTIC AIRFOILS FORCED BY CONTROL SURFACE MOTION AND GUSTS , Technical Memorandum
    Authors: A. V. Balakrishnan and John W. Edwards
    Report Number: NASA-TM-81351
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The time-domain equations of motion of elastic airfoil sections forced by control surface motions and gusts were developed for the case of incompressible flow. Extensive use was made of special functions related to the inverse transform of Theodorsen's function. Approximations for the special cases of zero stream velocity, small time, large and time are given. A numerical solution technique for the solution of the general case is given. Examples of the exact transient response of an airfoil are presented.
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    Report Date: August 1980
    No. Pages: 167
    Funding Organization: REPT-505-36-24
    Keywords:      Aeroelasticity; Aircraft Structures; Airfoils; Equations Of Motion; Flutter; Imcompressable Flow; Transient Response


  20. IMPROVED TEST METHODS FOR DETERMINING LIGHTNING-INDUCED VOLTAGES IN AIRCRAFT , Contractor Report
    Authors: K. E. Crouch and J. A. Plumer
    Report Number: NASA-CR-3329
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A lumped parameter transmission line with a surge impedance matching that of the aircraft and its return lines was evaluated as a replacement for earlier current generators. Various test circuit parameters were evaluated using a 1/10 scale relative geometric model. Induced voltage response was evaluated by taking measurements on the NASA-Dryden Digital Fly by Wire F-8 aircraft. Return conductor arrangements as well as other circuit changes were also evaluated, with all induced voltage measurements being made on the same circuit for comparison purposes. The lumped parameter transmission line generates a concave front current wave with the peak di/dt near the peak of the current wave which is more representative of lightning. However, the induced voltage measurements when scaled by appropriate scale factors (peak current or di/dt) resulting from both techniques yield comparable results.
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    Report Date: January 1980
    No. Pages: 106
    Notes: NASA Technical monitor: Wilton Lock


  21. A MODIFIED T-VALUE METHOD FOR SELECTION OF STRAIN GAGES FOR MEASURING LOADS , Technical Memorandum
    Authors: M. H. Tang
    Report Number: NASA-TM-85464
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: No Abstract Available.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 35
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    Report Date: January 1980
    No. Pages: 26
    Keywords:      Aerodynamic loads; Delta wings; Hypersonic flight; Low aspect ratio wings; Strain gages.
    Notes: Presented at Fall Meeting of the Western Regional Gage Comm. Soc. for Expt. Stress Analysis, China Lake, Calif., 16-17 Sep. 1980.


  22. THE EFFECT OF THERMAL STRESSES ON THE INTEGRITY OF THREE BUILT-UP AIRCRAFT STRUCTURES. , Technical Memorandum
    Authors: J. M. Jenkins
    Report Number: NASA-TM-81352
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A Mach 6 flight was simulated in order to examine heating effects on three frame/skin specimens. The specimens included: a titanium truss frame with a lockalloy skin; a stainless steel z-frame with a lockalloy skin; and a titanium z-frame with a lockalloy skin. Thermal stresses and temperature were measured on these specimens for the purpose of examining their efficiency, performance, and integrity. Measured thermal stresses were examined with respect to material yield strengths, buckling criteria, structural weight, and geometric locations. Principal thermal stresses were studied from the standpoint of uniaxial stress assumptions. Measured thermal stresses were compared to predicted values.
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    Report Date: November 1980
    No. Pages: 60
    Keywords:      Aircraft Structures; Structural Analysis; Thermal Stresses; Flight Simulation; Performance Tests; Stainless Steel; Temperature Measurement; Titanium Alloy


  23. A COMPUTER PROGRAM FOR CYCLIC PLASTICITY AND STRUCTURAL FATIGUE ANALYSIS , Contractor Report
    Authors: I. Kalev
    Report Number: NASA-CR-163101
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A computerized tool for the analysis of time independent cyclic plasticity structural response, life to crack initiation prediction, and crack growth rate prediction for metallic materials is described. Three analytical items are combined: the finite element method with its associated numerical techniques for idealization of the structural component, cyclic plasticity models for idealization of the material behavior, and damage accumulation criteria for the fatigue failure.
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    Report Date: November 1980
    No. Pages: 43
    Keywords:      Computer Programs; Crack Initiation; Cyclic Loads; Metal Fatigue; Plastic Properties; Structural Analysis; Crack Propagation; Elastoplasticity; Finite Element Analysis


  24. ASSESSMENT OF THE VISIBILITY IMPAIRMENT CAUSED BY THE EMISSIONS FROM THE PROPOSED POWER PLANT AT BORON, CALIFORNIA , Contractor Report
    Authors: R. W. Bergstrom, J. R. Doyle, C. D. Johnson, H. Y. Holman and M. A. Wojcik
    Report Number: NASA-CR-163103
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
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    Report Date: January 1980
    Notes: NASA Technical monitor: Tim Horton.
 
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