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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 91 records · Page 5

All sources NASA NTRS DOE OSTI

NASA NTRS1988

Parametric studies of advanced turboprops

The effects of geometric variables (sweep and twist) on the structural performance of advanced turboprops are investigated. The investigation is limited to aerodynamically efficient turboprops using an acceptable design configuration as a baseline. The baseline configuration is modified using a seven by seven array of independently varying sweep and twist parameters while maintaining acceptable aerodynamic efficiency. The turboprop structural performance is evaluated in terms of critical speeds, tip displacements, and vibration frequencies where geometric nonlinearities are included. The results obtained are presented in such a manner as to highlight the effects of sweep and twist on the structural performance of aerodynamically efficient turboprop configurations.

Maser, J. G.↗

DOE OSTI2025

Establishing a process-structure-property-performance framework for SLS additive manufacturing through integrated multiscale modeling

This study presents a comprehensive suite of high-fidelity computational models that integrate multiscale and multiphysics simulations to capture the full Selective Laser Sintering (SLS) additive manufacturing process—from initial melting and solidification to mechanical response under external loads. Process simulations are linked with mechanical analysis through Representative Volume Elements (RVEs), establishing a process-structure–property-performance framework. The interaction between laser light and polyamide 12 (PA12) powder is modeled, accounting for laser characteristics and the optical, thermal, and geometrical properties of the powder. The heat source is incorporated into a heat transfer model, coupled with crystallization kinetics and densification models to predict material density and crystallinity. The porosity distribution from the densification model and crystallinity interpolated from experimental data are used to construct the RVEs. A multi-mechanism constitutive model is then calibrated using mechanical tests to predict the stress–strain response. Simulation results show good agreement with experimental data in terms of porosity, crystallinity, and mechanical performance when sufficient laser power (62 W or higher) is used. This research supports the inverse design of 3D-printed structures by introducing a high-fidelity framework that combines multiscale and multiphysics modeling with experimental calibration for predictive and performance-driven additive manufacturing.

SLS↗

DOE OSTI2022

Direct Recycling of Lithium-Ion Battery Cathodes: A Multi-Stage Annealing Process to Recover the Pristine Structure and Performance

Direct recycling is an alternative low-cost process that retains the structure of the lithium-ion battery cathode rather than going through materials dissolution and repurification. While the process shows promise, various steps need to be better understood and studied to identify possible roadblocks, cost intensive steps, and needed variations in protocol that may be necessary based on the feedstock of recycled cathodes available. In this study, we have evaluated the process of thermal relithiation as it applies to end-of-life cathode materials. For recovered end-of-life cathodes, approximately 20% of the useable lithium has been lost due to solid electrolyte interface formation, parasitic reactions, and particle isolation; this lost lithium contributes to higher cell impedance and a gradual shift in electrode potentials. As a first step in the direct recycling process, this lithium needs to be restored not only to recover capacity but also to eliminate surface vacancies and hinder surface reconstruction that may increase impedance and impact performance. Here, we have optimized a coating method followed by a two-stage annealing process that restores a model delithiated NMC333 material to pristine performance. Comparisons to single-stage processes are made, and new characterization tools have been used to better understand the processes.

25 ENERGY STORAGE↗

DOE OSTI2025

The Impact of Catalyst Layer Composition and Structure on Performance and Durability of PEMWE Anodes

A study of various compositions of anodes for proton exchange membrane water electrolysis aimed at reducing precious metal content and system costs without compromising performance and durability is presented. A key challenge in current water electrolysis technologies is the reliance on high iridium loadings to ensure sufficient catalytic activity, electronic conductivity, and durability for the oxygen evolution reaction. To address this, catalyst layers based on the stable but kinetically limited rutile phase of iridium oxide are combined with platinum nanoparticles and carbon-based additives to improve structural properties and ink processability. By systematically varying the volume ratios of carbon to precious metals and ionomer to solids, compositional trends have been identified, and significant performance improvements have been achieved. Structural and elemental analysis confirms improved dispersion of platinum and iridium can be achieved, as well as electronic conductivity improvements within the catalyst layer. Polarization curve analysis has shown the ability of added Pt and C to significantly increase catalytic activity. These results highlight the potential positive impact of Pt and C on anode structure, composition, and cell performance.

36 MATERIALS SCIENCE↗

NASA NTRS2019

TriTruss: A New and Novel Structural Concept Enabling Modular Space Telescopes and Space Platforms

Modular structures that can be assembled on-orbit will be the backbone for all future persistent missions, including in-space assembled telescopes and platforms for science and communications. The TriTruss is a new and innovative structural module that has been conceived by researchers at the NASA Langley Research Center for platform and telescope applications. Some of the innovative features of the TriTruss include: very compact packaging for launch, the possibility of staged packaging, simple robotic deployment, ease of embedding payload components, an innovative structural connector that has linear structural performance, ease of module-to-module robotic assembly, design versatility, and ease of customizing its design for specific applications. This paper will introduce the TriTruss concept and describe how it can serve as the foundation for many different mission applications, in particular, a 20-meter diameter large space telescope and a beam-type platform that can host a variety of payloads and instruments. The geometry of the TriTruss will be described and the various truss design variables (such as truss depth, member diameter, material modulus, etc.) and each of their impacts on the truss performance will be illustrated. The TriTruss can be mapped to a variety of structural forms, such as beams, two-dimensional platforms and filled curved apertures (for antennas and telescopes), and examples will be illustrated. The TriTruss lends itself to a large variety of packaging schemes; the structural concepts associated with packaging and deployment will be described, as well as the means for robotically deploying TriTruss modules and locking them into their final configuration. TriTruss module-to-TriTruss module robotic assembly operations will also be described. Equations will be presented to structurally size TriTruss modules, such that when assembled into the final persistent platform, the platform achieves a desired level of global structural performance. A status of the TriTruss development will also be presented. This material will cover design and fabrication of TriTruss hardware for platform and telescope applications as well as structural testing of that hardware (the struts, connectors and platforms). Robotic assembly of TriTruss modules is also being performed, and the results of those tests will be summarized.

Doggett, William↗

NASA NTRS1980

Recent developments in the design, testing and impact-damage tolerance of stiffened composite panels

The structural technology of laminated filamentary-composite stiffened-panel structures under combined in-plane and lateral loadings is discussed. Emphasis is on analyzing the behavior of the structures under load, determining appropriate structural proportions for weight efficient configurations, and effects of impact damage and geometric imperfections on structural performance. Experimental data on buckling of panels under in-plane compression validate the analysis and sizing methods, and illustrate structural performance and efficiency obtained from representative structures. It is shown that the strength of panels under in-plane compression can be degraded by low-velocity impact damage, and data are presented which indicate that the matrix is a significant factor influencing tolerance to impact damage.

Williams, J. G.↗

DOE OSTI2021

Correlation of the Structure with Performance in MEH-PPV/dPS Thin Films Illuminated during Processing

Thin films containing conjugated polymers have been used in a wide array of optoelectronic devices, and much research has focused on the conformation of the conjugated polymer as a key aspect to tuning the performance of the resulting devices. White light exposure has been studied as a post-processing method to alter the film’s morphology and photoluminescence (PL) in systems composed of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and polystyrene (PS). To date, there have been few studies that correlate the changes in the depth profile with the PL performance of MEH-PPV/PS films. This study is designed to address this gap in knowledge. Thin films of MEH-PPV/dPS annealed above the glass transition temperatures (T g ) in an illuminated environment led to lower PL than that found in annealed samples that are not illuminated. However, at higher MEH-PPV loading in the blend film, the extent of variation of PL with illumination diminished. Additionally, time-of-flight secondary ion mass spectrometry and small-angle neutron scattering document the three-dimensional morphology of the films under illumination conditions, which are correlated with the changes in PL. Illumination during annealing compressed MEH-PPV-rich layers in the thin film blends at low loadings of MEH-PPV (below 10 wt %) but resulted in significant in-plane phase separation at higher loadings (above 15 wt %). Both changes increase interchain interactions and lower the PL of the illuminated samples. The changes in the depth profile significantly alter the PL of the films, while the in-plane phase separation affected the optoelectronic properties to a lesser degree. This work, therefore, provides insights into how illumination and film composition can be utilized to predictably alter the structure and optoelectronic performance of conjugated polymer blend films.

36 MATERIALS SCIENCE↗

DOE OSTI2022

NNSA Advanced Photon Source Sector Opportunities Workshop (Workshop Summary)

An NNSA-Argonne National Laboratory workshop to define NNSA and external partner mission needs and opportunities at the Advanced Photon Source was held February 15-17, 2022. This workshop summary provides a fresh look at NNSA’s evolving mission needs, partner agency and university interests, x-ray photon characteristics, and technical requirements to meet those needs. The workshop was organized according to four breakout groups: Coupling dynamic drivers to a synchrotron, High explosives and chemical sciences, Process-structure-performance: X-ray experiments to understand materials behaviors, and Process-structure-performance: manufacturing and aging. This summary report describes the workshop outcomes, and the preliminary conceptual design for a dedicated Defense Materials Science Sector (DMSS) at the Advanced Photon Source.

36 MATERIALS SCIENCE↗

NASA NTRS1999

An Air-Breathing Launch Vehicle Concept for Single-Stage-to-Orbit

The "Trailblazer" is a 300-lb payload, single-stage-to-orbit launch vehicle concept that uses air-breathing propulsion to reduce the required propellant fraction. The integration of air-breathing propulsion is done considering performance, structural and volumetric efficiency, complexity, and design risk. The resulting configuration is intended to be viable using near-term materials and structures. The aeropropulsion performance goal for the Trailblazer launch vehicle is an equivalent effective specific impulse (I*) of 500 sec. Preliminary analysis shows that this requires flight in the atmosphere to about Mach 10, and that the gross lift-off weight is 130,000 lb. The Trailblazer configuration and proposed propulsion system operating modes are described. Preliminary performance results are presented, and key technical issues are highlighted. An overview of the proposed program plan is given.

Trefny, Charles J.↗

NASA NTRS2014

Overview of the 6 Meter HIAD Inflatable Structure and Flexible TPS Static Load Test Series

To support NASAs long term goal of landing humans on Mars, technologies which enable the landing of heavy payloads are being developed. Current entry, decent, and landing technologies are not practical for this class of payloads due to geometric constraints dictated by current launch vehicle fairing limitations. Therefore, past and present technologies are now being explored to provide a mass and volume efficient solution to atmospheric entry, including Hypersonic Inflatable Aerodynamic Decelerators (HIADs). At the beginning of 2014, a 6m HIAD inflatable structure with an integrated flexible thermal protection system (TPS) was subjected to a static load test series to verify the designs structural performance. The 6m HIAD structure was constructed in a stacked toroid configuration using nine inflatable torus segments composed of fiber reinforced thin films, which were joined together using adhesives and high strength textile woven structural straps to help distribute the loads throughout the inflatable structure. The 6m flexible TPS was constructed using multiple layers of high performance materials to protect the inflatable structure from heat loads that would be seen during atmospheric entry. To perform the static load test series, a custom test fixture was constructed. The fixture consisted of a structural tub rim with enough height to allow for displacement of the inflatable structure as loads were applied. The bottom of the tub rim had an airtight seal with the floor. The centerbody of the inflatable structure was attached to a pedestal mount as seen in Figure 1. Using an impermeable membrane seal draped over the test article, partial vacuum was pulled beneath the HIAD, resulting in a uniform static pressure load applied to the outer surface. During the test series an extensive amount of instrumentation was used to provide many data sets including: deformed shape, shoulder deflection, strap loads, cord loads, inflation pressures, and applied static load.In this overview, the 6m HIAD static load test series will be discussed in detail, including the 6m HIAD inflatable structure and flexible TPS design, test setup and execution, and finally initial results and conclusions from the test series.

inflatable aerodynamic decelerator↗

NASA NTRS1989

Probability of failure and risk assessment of propulsion structural components

The probabilistic structural analysis method (PSAM) was developed to analyze the effects of fluctuating loads, variable material properties, and uncertain analytical models especially for high performance structures such as the Space Shuttle Main Engine turbopump blades. Risk is calculated after expensive service experience. However, probabilistic structural analysis provides a rational alternative method to quantify uncertainties in the structural performance and durability. NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) was developed as a probabilistic structural analysis computer code which integrates finite element methods and reliability algorithms, capable to predicting the probability distributions of structural response variables such as stress, displacement, natural frequencies, and buckling loads. This computer code is detailed.

Shiao, Michael C.↗

NASA NTRS2000

Integral Airframe Structures (IAS): Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs

The Integral Airframe Structures (IAS) program investigated the feasibility of using "integrally stiffened" construction for commercial transport fuselage structure. The objective of the program was to demonstrate structural performance and weight equal to current "built-up" structure with lower manufacturing cost. Testing evaluated mechanical properties, structural details, joint performance, repair, static compression, and two-bay crack residual strength panels. Alloys evaluated included 7050-T7451 plate, 7050-T74511 extrusion, 6013-T6511x extrusion, and 7475-T7351 plate. Structural performance was evaluated with a large 7475-T7351 pressure test that included the arrest of a two-bay longitudinal crack, and a measure of residual strength for a two-bay crack centered on a broken frame. Analysis predictions for the two-bay longitudinal crack panel correlated well with the test results. Analysis activity conducted by the IAS team strongly indicates that current analysis tools predict integral structural behavior as accurately as built-up structure. The cost study results indicated that, compared to built-up fabrication methods, high-speed machining structure from aluminum plate would yield a recurring cost savings of 61%. Part count dropped from 78 individual parts on a baseline panel to just 7 parts for machined IAS structure.

Munroe, J.↗

DOE OSTI2026

Direct Ab Initio Simulation of the Synthesis of BaZrO 3 and the Microstructure Impacts on Proton Transport

Controlling and predicting the processing-structure-performance relationship in functional materials is a grand challenge in materials science, with important implications for a wide range of emerging applications; a high fidelity understanding of the performance impact of microstructures formed under synthesis conditions is required to develop advanced materials, such as solid-state fuel cells and electrolyzers. Using the ceramic BaZrO 3 as a case study, we directly simulate the synthesis and investigate how proton transport is dictated by microstructures. We develop a framework that couples density functional theory (DFT), machine-learning interatomic potential (MLIP) driven molecular dynamics, and grand canonical Monte Carlo to perform large-scale, microstructure-resolved, atomistic simulations of proton transport in experimentally representative polycrystalline structures. Our fully ab initio approach, using a MLIP as a proxy for DFT, allows us to quantify the competition between two distinct diffusion mechanisms: one associated with grain-boundary regions and another within grains. When the impacts of grain boundaries are taken into account, proton transport exhibits substantial deviation from the bulk oxide limit. This addresses long-standing discrepancies between theory and experiments. Our integrated approach provides atomistic insight into microstructure-dependent proton pathways in BaZrO 3 and establishes a general protocol for predicting processing-structure-performance relationships.

organic↗

NASA NTRS1992

Screening programme to select a resin for Gravity Probe-B composites

The Gravity Probe-B (GP-B) program undertook a screening program to select a possible replacement resin for the E-787 resin currently used in composite neck tubes and support struts. The goal was to find a resin with good cryogenic and structural properties, low-helium permeation and an easily repeatable fabrication process. Cycom 92, SCI REZ 081 and RS-3 were selected for comparison with E-787. Identical composite tubes made from each resin and gamma-alumina fiber (85 percent Al2O3, 15 percent SiO2) were evaluated for cryogenic and structural performance and for processability. Cryogenic performance was evaluated by measuring low-temperature permeation and leaks to determine cryogenic strain behavior. Structural performance was evaluated by comparing the resin-dominated shear strength of the composites. Processability was evaluated from fabrication comments and GP-B's own experience. SCI REZ 081 was selected as the best overall resin with superior strength and cryogenic performance and consistent processability.

Will, E. T.↗

NASA NTRSDate not supplied

A Design Framework for Thick and Thin Tow-Steered Composites Using Mechanics of Structure Genome

The design of tow-steered composites is one of the most popular and promising topics under the class of variable stiffness structures. In this work, the authors propose a new design framework and tool for the optimization of tow-steered composites. Mechanics of structure genome (MSG) provides accurate computation of plate/shell section properties including thick and highly curved structures. The computed section properties can be directly used in commercial computer-aided engineering tools. Tow-steered composites are modeled through a design framework wherein tow paths are parameterized in a general way and projected onto a finite element mesh, and MSG calculates the local shell/plate properties. The result is a complete workflow from design parameter input to structural performance evaluation. An open-source optimization software package is used to enable constrained optimization of structural stiffness for the broad tow-steered composite design space. Numerical examples are provided to demonstrate the capabilities of this tool and the promise and potential of tow-steered designs that optimize structural performance while satisfying manufacturing constraints.

Su Tian↗

NASA NTRSDate not supplied

A Design Framework for Thick and Thin Tow-Steered Composites Using Mechanics of Structure Genome

Su Tian↗

NASA NTRS1983

Space shuttle orbiter leading-edge flight performance compared to design goals

Thermo-structural performance of the Space Shuttle orbiter Columbia's leading-edge structural subsystem for the first five (5) flights is compared with the design goals. Lessons learned from thse initial flights of the first reusable manned spacecraft are discussed in order to assess design maturity, deficiencies, and modifications required to rectify the design deficiencies. Flight data and post-flight inspections support the conclusion that the leading-edge structural subsystem hardware performance was outstanding for the initial five (5) flights.

Curry, D. M.↗

NASA NTRS1988

Techniques for assessment of flexible space structure control performance

Several multivariable concepts are presently applied to both the open-loop and closed-loop analysis of a wrap-rib antenna space structure. After evaluating the alternative placements of sensors and actuators by means of controllability, observability, and transmission-zero concepts, the linear quadratic gaussian/loop transfer recovery method is used to synthesize a control law for suppression of the transient vibrations that are typically encountered during maneuvers. The integration of these techniques and associated computer programs into a larger spacecraft design system is also discussed.

Rowell, Lawrence F.↗