SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
A cable-driven additive manufacturing system includes an end effector configured for linear translation within a three-dimensional workspace, an aerial hoist suspending the end effector by at least one suspension cable, a plurality of base stations disposed below the aerial hoist, and control cables running from each of the base stations to the end effector.
An assembly for additive manufacturing includes a build housing including a base, a print head, and a print head support connected to the base for supporting the print head above the base. A driver system is provided for moving the print head and the base relative to one another. A build platform comprising a build support and at least one platen. The build support can be detachably engageable to the housing. The platens can be detachably engageable to the build support. The build support can include registration structure for registering the position of the build support relative to the build housing. A method of additive manufacturing is also disclosed.
A method for rapid manufacturing of three dimensional discontinuous fiber preforms is provided. The method includes the deposition of a polymeric material containing fibers on a surface to form a tailored charge for compression molding. The reinforced polymeric material may be a thermoplastic or a reactive polymer with viscosity low enough to allow flow through an orifice during deposition, yet high enough zero shear viscosity to retain the approximate shape of the deposited charge. The material can be deposited in a predetermined pattern to induce the desired mechanical properties through alignment of the fibers. This deposition can be performed in a single layer or in multiple layers. The alignment is achieved passively by shear alignment of the fibers or actively through fiber orientation control or mixing. The fibers can be of the desired material, length, and morphology, including short and long filaments.
Systems, methods and unmanned agents for collaboratively controlling agents in a collaborative network by one or more agents continuously simulating numeric models of one or more other agents in the network to dramatically reduce the computational bandwidth required between agents, and improve the quality of shared estimates of the agent locations as well as the locations and characteristics of other objects of interest, e.g. targets. Bandwidth is reduced by using the models to intelligently filter data before communicating.
Apparatus include divergence optics removably coupled to receive a probe beam in a first imaging mode to cause the probe beam to diverge before impinging on a first area of a target surface, and to not receive the probe beam in a second imaging mode to cause the probe beam to impinge on a second area of the target surface smaller than the first area, collection optics configured to receive, in response to the probe beam, luminescence light emitted from the first area and spectral light emitted from the second area, and an optical detector coupled to the collection optics, wherein the optical detector includes a luminescence imaging detector portion and a spectral imaging detector portion adjacent to the luminescence imaging detector portion, wherein the luminescence imaging detector portion is configured to receive the luminescence light emitted from the first area and the spectral imaging detector portion is configured to receive the spectral light from the second area.
A packing device for mass and heat transfer with a subject fluid includes a housing having opposing ends, and subject fluid openings at each opposing end defining a subject fluid flow path for at least one subject fluid flowing through the packing device. A plurality of mass and heat transfer plates each include an interior heat exchange fluid channel disposed between interior heat transfer surfaces of the mass and heat transfer plates. A heat exchange fluid inlet and fluid outlet can supply and remove heat exchange fluid to the heat exchange fluid channels of the mass and heat transfer plates. The mass and heat transfer plates can be oriented to define there between fluid flow channels for the subject fluid. A method and system for mass and heat transfer with a subject fluid, and a method and system for the removal of CO2 from a gas stream are disclosed.
A system and method for improving additive manufacturing, including additive manufacturing toolpaths, is provided. The system and method includes a toolpath generator that obtains initial toolpaths of an object, identifies isolated paths in the toolpaths, and adds bridge connections between neighboring isolated paths in each layer to improve the toolpaths. The bridge connections facilitate the continuous and non-stop deposition of each layer according to improved toolpaths during additive manufacture, which can reduce total deposition time and improve the resultant additive manufacture.
Systems and methods for generating graded lattice structures that can be used as infill for additively manufactured articles. Tailored sectioning and field-based smoothing are modified polygon, e.g., circle, packing algorithms that adjust the size of the circles based on physical field data to adapt the infill generation process to a field expected to be experienced by the article. Molecular dynamically generated lattice infill is based on force balancing a node distribution instead of a circle packing. Field data can be utilized to adjust the spacing of the node distribution according to a force balance equilibrium model that accounts for the field expected to be experienced by the article being additively manufactured. The resultant non-uniform honeycomb structures from tailored sectioning, field-based smoothing, and force-balancing robustly and efficiently address the connection issues with traditional non-uniform lattice structures.
Explore the source record for details and available documents.
A method and a system for automated plant surveillance and manipulation are provided. Pursuant to the method and the system, images of target plants are obtained through a machine vision system having multiple cameras. The obtained images of the target plants are processed to determine tissue candidates of the target plants and to determine a position and an orientation of each tissue candidate. A tool is manipulated, based on the position and the orientation of each tissue candidate, to excise each tissue candidate to obtain tissue samples. The tissue samples are transported for subsequently manipulation including live processing of the tissue samples or destructive processing of the tissue samples.
Systems and methods for generating molecular dynamic graded lattice structures that can be used as infill for additively manufactured articles. Molecular dynamically generated lattice infill is based on force balancing a node distribution instead of a circle packing. Field data can be utilized to adjust the spacing of the node distribution according to a force balance equilibrium model that accounts for the field expected to be experienced by the article being additively manufactured. The resultant non-uniform honeycomb structures from force-balancing robustly and efficiently address the connection issues with traditional non-uniform lattice structures.
A simulation-assisted additive manufacturing system and method for generating an anisotropic compensation to account for non-uniform deformation due to additive manufacturing and service loading. The predicted deformation may not be fully defined. The present disclosure provides a system and method for estimating the missing deformation data through regression analysis. The present disclosure also provides an integrated framework where the various simulated-assisted design modules are configured for two-way communication and sharing access to changes to the model.
The present subject matter relates to systems, devices, and methods of enhancing carbon fiber dispersion in wet-laid nonwovens. A quantity of fibers is deposited in a medium, and each of one or more stirring elements is moved in a pattern to mechanically agitate the medium. In some embodiments, moving each of the one or more stirring elements includes moving the one or more stirring elements in complementary patterns to induce a chaotic advection current within the medium.
The 27 in-service double-shell tank (DST) systems at Hanford provide interim storage for nearly 56 million gallons of nuclear and hazardous chemical legacy waste. The safe and reliable storage of the waste is critical to the site's extended cleanup mission. While in service, the leak integrity of the DSTs must be demonstrated to satisfy the Washington Administrative Code, inform decisions on tank management, and gauge fitness for continued service beyond originally intended design lives. The carbon steel plates and welds that comprise DST primary tank sidewalls and lower knuckles are routinely 'sampled' for volumetric non-destructive testing using ultrasonic inspection technology to determine whether corrosion pitting, cracking, or general corrosion are occurring that could compromise tank leak integrity. However, the carbon steel plates and welds that comprise the bottoms of primary tanks have not been thoroughly inspected since the DSTs were constructed (i.e., since 1968-1986) due to limited physical access to the exterior tank bottoms. The Robotic Air-slot Volumetric Inspection System, or 'RAVIS,' is being engineered to overcome the challenge of tank bottom in-service inspection. The system will be deployed under primary tanks within the small cooling channels/air-slots in the refractory pads upon which the tanks rest and will use ultrasonic guided wave inspection technology to volumetrically inspect physically inaccessible regions that make up ∼90% of a tank bottom, as well as regions that are physically accessible from the air-slots but comprise only ∼10% of a tank bottom. This paper describes the air-slot sensor and robotic deployment system and focuses on the testing approach and methods that are being applied to support (1) design feedback and performance acceptance (requirement verification) and (2) performance repeatability/reliability assessments (qualification) to ensure the RAVIS is prepared for successful inservice inspections of primary tank bottoms. Test progress made against the test plan, the results of 2019 testing, and the future outlook are included. (authors)
Polymer additive manufacturing (AM) technology is rapidly growing and its transition to become an advanced manufacturing technique now offers possibilities for unconventional applications. One of these potential applications is on site additive manufacturing of power poles. During natural incidents such as storms and hurricanes, power lines can be severely damaged and there may not be sufficient spare power poles to replace. In such situations, additive manufacturing of power poles on site can offer a fast, temporary solution during emergencies. The ability of freeform manufacturing of parts with complex geometries makes large scale AM attractive for various applications; however, due to residual stress build up and need for different mechanical requirements for different applications, reinforcement of the AM feedstock is necessary. In addition to carbon and glass fibers, bio-derived fibers can also be used as a reinforcing phase, both to utilize the natural resources at the emergency area and in terms of long-term sustainability. In this project, design and additive manufacturing of a 13.1 m power pole was demonstrated. Three different feedstock material options (polystyrene, cellulose ester and polycarbonate reinforced with glass and bamboo fibers) and two different pole designs were investigated. As-printed part tensile properties both in printing and interlayer directions were measured and a power pole was printed as six pieces and put together successfully. Finally, a conceptual design of a portable power pole manufacturing approach was proposed.
The CHIPS R&D project focuses on development of low-cost water Cherenkov neutrino detectors through novel design strategies and resourceful engineering. This work presents an end-to-end DAQ solution intended for a recent 5 kt CHIPS prototype, which is largely based on affordable mass-produced components. Much like the detector itself, the presented instrumentation is composed of modular arrays that can be scaled up and easily serviced. A single such array can carry up to 30 photomultiplier tubes (PMTs) accompanied by electronics that generate high voltage in-situ and deliver time resolution of up to 0.69 ns. In addition, the technology is compatible with the White Rabbit timing system, which can synchronize its elements to within 100 ps. While deployment issues did not permit the presented DAQ system to operate beyond initial evaluation, the presented hardware and software successfully passed numerous commissioning tests that demonstrated their viability for use in a large-scale neutrino detector, instrumented with thousands of PMTs.
The short-range region (r < 1 fm) of the nucleon-nucleon potential may be studied via deuteron electro-disintegration. Such an experiment was done at Hall C of Jefferson Lab at 4-momentum transfers of Q^2 = 4.07 (GeV/c)^2 and reaching missing momenta up to 900 MeV/c. At such settings, complications arising from Meson Exchange Currents (MEC) and Isobar Currents are expected to be signifi cantly minimized, as well as Final State Interactions (FSI) at recoiling angles of ¿_Xq ~ 40 deg. This makes comparisons of experimental and theoretical cross sections less model dependent. A luminosity study was done to determine the reduction of liquid deuterium targets with increasing beam current. A 2.8% in the charge yield was found between 0 to 70 µA. Electron scattering from the walls of the target chamber was determined to be negligible, but caution was taken by considering scattering events away from the walls. A neutron was found to be contained in the missing mass spectrum for each missing momentum setting. Extraction of the deuteron total cross section is still on going.