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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.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaSr4(FeAs)10 by Materials Project

NaSr4(FeAs)10 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Na–As bond lengths are 3.28 Å. Sr2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Sr–As bond distances ranging from 3.25–3.32 Å. There are two inequivalent Fe+2.10+ sites. In the first Fe+2.10+ site, Fe+2.10+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. In the second Fe+2.10+ site, Fe+2.10+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Sr2+, and four Fe+2.10+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to four equivalent Sr2+ and four equivalent Fe+2.10+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Ba(FeAs)6 by Materials Project

K2Ba(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of K–As bond distances ranging from 3.32–3.45 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.38–3.41 Å. There are two inequivalent Fe+2.33+ sites. In the first Fe+2.33+ site, Fe+2.33+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. In the second Fe+2.33+ site, Fe+2.33+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. There are two shorter (2.31 Å) and two longer (2.32 Å) Fe–As bond lengths. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to three equivalent K1+, one Ba2+, and four Fe+2.33+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to three equivalent K1+, one Ba2+, and four equivalent Fe+2.33+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and four Fe+2.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2Na(FeAs)6 by Materials Project

NaBa2(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Na–As bond distances ranging from 3.36–3.40 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.32–3.48 Å. There are two inequivalent Fe+2.17+ sites. In the first Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. In the second Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.33 Å. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Ba2+, and four Fe+2.17+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Ba2+, and four equivalent Fe+2.17+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent Na1+, two equivalent Ba2+, and four Fe+2.17+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KBa2(FeAs)6 by Materials Project

KBa2(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are four shorter (3.39 Å) and four longer (3.43 Å) K–As bond lengths. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.35–3.49 Å. There are two inequivalent Fe+2.17+ sites. In the first Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are two shorter (2.32 Å) and two longer (2.33 Å) Fe–As bond lengths. In the second Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are two shorter (2.34 Å) and two longer (2.35 Å) Fe–As bond lengths. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one K1+, three equivalent Ba2+, and four equivalent Fe+2.17+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to one K1+, three equivalent Ba2+, and four Fe+2.17+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and four Fe+2.17+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Band-selective gap opening by a C 4 -symmetric order in a proximity-coupled heterostructure Sr 2 VO 3 FeAs

Significance Heterostructures of correlated electronic systems offer versatile platforms for various types of quantum phases and their transitions. A common wisdom states that the proximity coupling between constituent layers plays a secondary role, because it is much weaker than the intralayer interactions. In this work, we present a counterexample of the belief. Namely, the proximity coupling between localized spins and itinerant electrons stabilizes an exotic electronic state with band-selective gap opening whose observation is done in a correlated heterostructure Sr 2 VO 3 FeAs. Our finding highlights that the proximity coupling can be an effective knob for exotic phases in correlated heterostructures.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Bim-to-fea Conversion Program

The purpose of this program is to enable interoperability between BIM-based architectural design software (i.e., Revit, ArchiCAD, AVEVA E3D) to structural analysis software (i.e., SAP2000). The program takes in BIM building model data via the IFC file format, automatically transforms the architectural coordination entities (structural beams, columns, slabs, walls) to structural analysis entities (i.e., finite element space frames and shells), automatically adjusts the connectivity of the structural analysis entities, and finally exports the structural analysis entities as a structural analysis model contained within a new IFC file. For example, a 3D building in Revit can be exported to an IFC file, run through this BIM-to-FEA program, then the exported IFC can be inputted into SAP2000.

Crowder, Nicholas [Idaho National Laboratory (INL)↗
NASA NTRS2000

Composite Flywheels Assessed Analytically by NDE and FEA

As an alternative to expensive and short-lived lead-acid batteries, composite flywheels are being developed to provide an uninterruptible power supply for advanced aerospace and industrial applications. Flywheels can help prevent irregularities in voltage caused by power spikes, sags, surges, burnout, and blackouts. Other applications include load-leveling systems for wind and solar power facilities, where energy output fluctuates with weather. Advanced composite materials are being considered for these components because they are significantly lighter than typical metallic alloys and have high specific strength and stiffness. However, much more research is needed before these materials can be fully utilized, because there is insufficient data concerning their fatigue characteristics and nonlinear behavior, especially at elevated temperatures. Moreover, these advanced types of structural composites pose greater challenges for nondestructive evaluation (NDE) techniques than are encountered with typical monolithic engineering metals. This is particularly true for ceramic polymer and metal matrix composites, where structural properties are tailored during the processing stages. Current efforts involving the NDE group at the NASA Glenn Research Center at Lewis Field are focused on evaluating many important structural components, including the flywheel system. Glenn's in-house analytical and experimental capabilities are being applied to analyze data produced by computed tomography (CT) scans to help assess the damage and defects of high-temperature structural composite materials. Finite element analysis (FEA) has been used extensively to model the effects of static and dynamic loading on aerospace propulsion components. This technique allows the use of complicated loading schemes by breaking the complex part geometry into many smaller, geometrically simple elements.

Abdul-Aziz, Ali↗
NASA NTRS2003

Structural Anomalies Detected in Ceramic Matrix Composites Using Combined Nondestructive Evaluation and Finite Element Analysis (NDE and FEA)

Most reverse engineering approaches involve imaging or digitizing an object and then creating a computerized reconstruction that can be integrated, in three dimensions, into a particular design environment. The rapid prototyping technique builds high-quality physical prototypes directly from computer-aided design files. This fundamental technique for interpreting and interacting with large data sets is being used here via Velocity2 (an integrated image-processing software, ref. 1) using computed tomography (CT) data to produce a prototype three-dimensional test specimen model for analyses. A study at the NASA Glenn Research Center proposes to use these capabilities to conduct a combined nondestructive evaluation (NDE) and finite element analysis (FEA) to screen pretest and posttest structural anomalies in structural components. A tensile specimen made of silicon nitrite (Si3N4) ceramic matrix composite was considered to evaluate structural durability and deformity. Ceramic matrix composites are being sought as candidate materials to replace nickel-base superalloys for turbine engine applications. They have the unique characteristics of being able to withstand higher operating temperatures and harsh combustion environments. In addition, their low densities relative to metals help reduce component mass (ref. 2). Detailed three-dimensional volume rendering of the tensile test specimen was successfully carried out with Velocity2 (ref. 1) using two-dimensional images that were generated via computed tomography. Subsequent, three-dimensional finite element analyses were performed, and the results obtained were compared with those predicted by NDE-based calculations and experimental tests. It was shown that Velocity2 software can be used to render a three-dimensional object from a series of CT scan images with a minimum level of complexity. The analytical results (ref. 3) show that the high-stress regions correlated well with the damage sites identified by the CT scans and the experimental data. Furthermore, modeling of the voids collected via NDE offered an analytical advantage that resulted in more accurate assessments of the material s structural strength. The top figure shows a CT scan image of the specimen test section illustrating various hidden structural entities in the material and an optical image of the test specimen considered in this study. The bottom figure represents the stress response predicted from the finite element analyses (ref .3 ) for a selected CT slice where it clearly illustrates the correspondence of the high stress risers due to voids in the material with those predicted by the NDE. This study is continuing, and efforts are concentrated on improving the modeling capabilities to imitate the structural anomalies as detected.

Abdul-Aziz, Ali↗
NASA NTRS2019

Automatic Incorporation of Flaws into Cad and FEA Models Based On Measured NDE Data

Automatic incorporation of non-destructive evaluation (NDE) data into CAD and finite element (FE) models for structural analysis is essential for accurate residual-life and strength analyses of composite structures. Currently, two significant but independent challenges exist for incorporating NDE data in such analyses: interpretation of the NDE signals to locate and characterize the structural defects and the incorporation of that information into structural analysis tools. The first challenge will be addressed through linear inversion of calculated synthetic responses generated by a simulation engine to evaluate flaw size, location, and other characteristics. The second challenge will be addressed by building on prior and parallel defect modeling efforts to integrate suitable flaw models into the CAD/finite-element representation of a specimen. Ultrasonic NDE information is usually represented using C-Scans of time-of-flight or intensity information. Other modalities such as thermography and computed tomography (CT) could also be used to characterize the structure. This information will first be projected into material coordinates and then aligned with the specimen’s finite element mesh. The NDE data can then be incorporated by inserting flaw geometry into the CAD and FE analysis model and automatic modification of local material properties and boundary conditions. This process will enable the use of structural analysis tools even for practical modalities such as ultrasound and thermography which may not directly give accurate-enough geometric information to fully define the flaw. The full flaw characteristics will be inferred using prior expert and modeling knowledge to categorize flaw signatures. Outputs for this project will include demonstrated methods for creating structural analysis geometric models that incorporate flaw characterization information; these models can then be used directly in popular commercial FEA software. In addition, the primary deliverable for the project will include a software that will be able to automatically incorporate different kinds of flaws into an existing FE models. The models will be generated in standard file formats to enable direct import into the analysis software.

Adarsh Krishnamurthy↗
DOE OSTI2021

Design of High-Deflection Foils MHK Applications - FEA models

The Ocean Renewable Power Company's (ORPC's) goal is to design, develop, and test hydrofoils with large deflections. The effects of the deflections on cross-flow turbine performance would be evaluated in order to inform design considerations for full-scale water turbines and other marine hydrokinetic devices. Finite element models - NASTRAN files Model scale turbines tested in UNH tow tank Model loads from CFD models

16 TIDAL AND WAVE POWER↗
DOE OSTI2020

Materials Data on Eu(FeAs)2 by Materials Project

EuFe2As2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Eu2+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Eu–As bond lengths are 3.19 Å. Fe2+ is bonded to four equivalent As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.31 Å. As3- is bonded in a 4-coordinate geometry to four equivalent Eu2+ and four equivalent Fe2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs(FeAs)2 by Materials Project

CsFe2As2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Cs1+ is bonded in a distorted body-centered cubic geometry to eight equivalent As3- atoms. All Cs–As bond lengths are 3.66 Å. Fe+2.50+ is bonded to four equivalent As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. As3- is bonded in a 8-coordinate geometry to four equivalent Cs1+ and four equivalent Fe+2.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(FeAs)2 by Materials Project

SrFe2As2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr2+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Sr–As bond lengths are 3.29 Å. Fe2+ is bonded to four equivalent As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. As3- is bonded in a 8-coordinate geometry to four equivalent Sr2+ and four equivalent Fe2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(FeAs)2 by Materials Project

BaFe2As2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Ba–As bond lengths are 3.42 Å. Fe2+ is bonded to four equivalent As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. As3- is bonded in a 8-coordinate geometry to four equivalent Ba2+ and four equivalent Fe2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb(FeAs)2 by Materials Project

RbFe2As2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Rb1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Rb–As bond lengths are 3.46 Å. Fe+2.50+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. As3- is bonded in a 8-coordinate geometry to four equivalent Rb1+ and four equivalent Fe+2.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(FeAs)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(FeAs)2 by Materials Project

CaFe2As2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca2+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Ca–As bond lengths are 3.17 Å. Fe2+ is bonded to four equivalent As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.31 Å. As3- is bonded in a 9-coordinate geometry to four equivalent Ca2+ and four equivalent Fe2+ atoms.

36 MATERIALS SCIENCE↗