Abstract: This invention is a process for producing composite laminates containing interlaminar disbonds of controlled sizes, shapes, and positions within a composite structure. A composite layer is provided for later inclusion within a laminate. The surfaces of this composite layer are solvent cleaned and sandblasted, except in desired disbond areas, which are coated with a releasing surface. A template to mask the bond areas is employed to obtain disbond areas of controlled shapes and sizes. The resulting composite layer is then used in the subsequent manufacture of a laminate, whereby faulty adhesion in the laminate can be studied with prior knowledge of the size, shape, and location of the disbond areas.

Abstract: A metallic outer sleeve 10 is provided which is capable of enveloping a hollow metallic inner member 12 having continuous reinforcing fibers 14 attached to the distal end thereof. Inner member 12 is then introduced into outer sleeve 10 until inner member 12 is completely enveloped by outer sleeve 10. A liquid matrix member 20 is then injected into space 22 between inner member 12 and outer sleeve 10. A pressurized heat transfer medium 23 is flowed through the inside of inner member 12, thereby forming a fiber reinforced matrix composite material 26. The wall thicknesses of both inner member 12 and outer sleeve 10 are then reduced to the appropriate size by chemical etching, to adjust the thermal expansion coefficient of the metal-clad composite structure 28 to the desired value.

Abstract: A robotic hand having a plurality of fingers, each having a plurality of joints pivotally connected one to the other, with actuators connected at one end to an actuating and control mechanism mounted remotely from the hand and at the other end to the joints of the fingers for manipulating the fingers and passing externally of the robot manipulating arm in between the hand and the actuating and control mechanism. The fingers include pulleys to route the actuators within the fingers. Cable tension sensing structure mounted on a portion of the hand are disclosed, as is the covering of the tip of each finger with a resilient and pliable friction enhancing surface.

Abstract: A hybrid butterfly valve has a stationary seat and a valve closure disk which may rotate together with an actuating shaft from the fully open position to a position wherein the disk is aligned with the seat, and thereafter may be moved linearly into sealing relationship with the seat. The disk is supported by brackets having an elongated slot through which the shaft extends, the brackets being adapted to move linearly relative to the shaft. Cams fastened to the shaft initiate a 90.degree. rotation of the disk from the fully open position to the position where the valve disk is aligned with the seat, and the cams act thereafter in conjunction with followers carried by the disk to move the disk and the brackets linearly.

Abstract: A magnetic attachment mechanism adapted for interfacing with the manipulator arm (11) of a remote manipulator system and comprising a pair of permanent magnets (31,32) of rare earth material which are arranged in a stator-rotor relationship. The rotor magnet (32), is journalled for rotation about its longitudinal axis between pole plates (35,36) of the stator magnet (31), each of which includes an adhering surface (35a,36a). In a first rotary position corresponding to the "ON" condition, each of the poles of the rotor magnet (32) is closely adjacent a stator magnet pole plate of like polarity whereby the respective magnet fields are additive for producing a strong magnetic field emanating from the adhering surfaces (35a,36a) for attracting a ferrous magnetic plate 20, or the like, affixed to the payload (20 or 50).

Abstract: A process for manufacturing a low density ceramic powder which can be formed to make a lightweight material for insulation or other construction. The ceramic product made from the process has a final density of less than 25% to about 1% of its theoretical weight of the ceramic powder. The ceramic product is lightweight and can be made to withstand high temperatures greater than 1400.degree. C.

Abstract: In a parallel processing computer system with multiple processing units and shared memory, a method is disclosed for uniformly balancing the aggregate computational load in, and utilizing a minimal memory by, a network having identical computations to be executed at each connection therein. Read-only and read-write memory are subdivided into a plurality of partitions, and the computational load is subdivided into a plurality of process sets, which function like artificial processing units. Said plurality of process sets is iteratively merged and reduced to the number of processing units without exceeding the balance load. Merger is based upon the value of a partition threshold, which is a measure of the memory utilization. The turnaround time and memory savings of the instant method are functions of the number of processing units available and the number of partitions into which memory is subdivided.

Abstract: A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the "measured length" of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor.

Abstract: Actuated forebody strakes provide yaw control at high angles of attack. In one embodiment, the strakes are axially slidable in the forebody to be deployed out of slots provided for the strakes in the forebody. In another embodiment, the strakes are pivotally connected at the tip of the strakes to pivot radially outwardly out of the slots provided in the forebody. In another embodiment, the forebody is provided with either a single strake or two strakes and the forebody is rotatable to vary the radial location of the strake or strakes. All embodiments achieve significant yaw control capability over a wide angle of attack and sideslip ranges.

Abstract: The invention is a Clock for synchronizing operations within a high-speed, distributed data processing network. The clock is actually a distributed system comprising a Central Clock and multiple Site Clock Interface Units (SCIU's) which are connected by means of a fiber optic star network and which operate under control of separate clock software. The presently preferred embodiment is as a part of the flight simulation system now in current use at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC), Hampton, Va.

Abstract: This device is concerned with sealing the sliding interfaces between structural panels that are roughly perpendicular to each other or whose edges are butted against one another. The gap which the seal element must seal is not uniform along the seal length requiring significant seal flexibility.The seal 10 is mounted in a rectangular groove 14 in a moveable structural panel 16. The seal comprises a plurality of rectangular shaped wafers 12 stacked next to one another and preloaded in the axial direction to minimize leakage between wafers. The wafers are laterally preloaded to maintain sealing contact along the wafer faces which engage the adjacent wall of a sidewall 18 using one of several approaches, such as the pressurized linear bellows 22. The seal accomodates distortions in the adjacent panel by relative sliding between adjacent wafers.Leakage between wafers is further minimized with good wafer surface finishes.

Abstract: A multiple layer dielectric for use in a hot-film laminar separation layer 21. The multiple layer dielectric substrate is formed by depositing a first layer 22 of a thermoplastic polymer such as on an electrically conductive substrate such as the metal surface 23 of a model 24 to be tested under cryogenic conditions and high Reynolds numbers. Next, a second dielectric layer 26 of fused silica is formed on the first dielectric layer 22 of thermoplastic polymer. A resistive metal film is deposited on selected areas of the multiple layer dielectric substrate of form one or more hot-film sensor elements 27 to which aluminum electrical circuits 28 deposited upon the multiple layered dielectric substrate are connected.

Abstract: Apparatus is provided for obtaining a single crack in fatigue loading which emanates from a predetermined starting notch in a test specimen. This crack propagates in a direction in line with that of the applied Mode II load. The loading may be performed either monotonically or in a cyclic fatigue.

Abstract: A liquid supply control is disclosed for a heat transfer system which transports heat by liquid-vapor phase change of a working fluid. An assembly (10) of monogroove heat pipe legs (15) can be operated automatically as either heat acquisition devices or heat discharge sources. The liquid channels (27) of the heat pipe legs (15) are connected to a reservoir (35) which is filled and drained by respective filling and draining valves (30, 32). Information from liquid level sensors (50, 51) on the reservoir (35) is combined (60) with temperature information (55) from the liquid heat exchanger (12) and temperature information (56) from the assembly vapor conduit (42) to regulate filling and draining of the reservoir (35), so that the reservoir (35) in turn serves the liquid supply/drain needs of the heat pipe legs (15), on demand, by passive capillary action (20, 28).

Abstract: A means for extracting rotational energy from the vortex created at aircraft wing tips which consists of a turbine with blades located in the crossflow of the vortex and attached downstream of the wingtip. The turbine 30 has blades 40, 41, 42 and 43 attached to a core 45. When the aircraft is in motion, rotation of core 45 transmits energy to a centrally attached shaft 50. The rotational energy thus generated may be put to use within the airfoil 20 or aircraft fuselage 10.

Abstract: A body restraint system (30) allows the user's body (10) to be in the zero gravity neutral posture. The system (30) includes a waist restraint (32) in the form of a curved, padded unit (34) containing a retractable belt (36) coiled on a spring loaded capstan (38) with a buckle (40) extending from front (42) of the unit (34). A second belt (44) is fastened around the user's waist (16). A clasp (46) is configured to engage the buckle (40). The waist restraint (32) is positioned near foot restraints (52). The foot restraints (52) have foot platforms (59) with pads (60) of a suitable two part attaching material, such as the fasteners available from Minnesota Mining and Manufacturing Company under the trademark Scotchmate Duallock. A mating pad (62) of the material is provided on soles (64) of cotton net shoes (66).

Abstract: A real-time dynamic holographic image storage device uses four-wave mixing in a pair of photorefractive crystals. An oscillation is produced between the crystals which can be maintained indefinitely after the initial object beam is discontinued. The object beam produces an interference patORIGIN OF THE INVENTIONThe invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.

Abstract: An external flow, liquid sheet radiator apparatus adapted for space applications has as its radiating surface a thin stable liquid sheet formed by fluid flow through a very narrow slit affixed to the sheet generator.

Abstract: A method and apparatus for testing steel components for temper embrittlement uses magneto-acoustic emission to nondestructively evaluate the component. Acoustic emission signals occur more frequently at higher levels in embrittled components. A pair of electromagnets are used to create magnetic induction in the test component. Magneto-acoustic emission signals may be generated by applying an AC current to the electromagnets. The acoustic emission signals are analyzed to provide a comparison between a component known to be unembrittled and a test component. Magnetic remanence is determined by applying a DC current to the electromagnets, then turning the magnets off and observing the residual magnetic induction.

Abstract: In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus having a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output of the driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.