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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Two-dimensional modelling of compressive failure in delaminated laminates

An analytical model is developed to assess the compressive strength criticality of near-surface interlaminar defects in laminated composites. The delaminated region is elliptic in shape, separating a thick isotropic plate from a thin orthotropic layer whose material axes coincide with the ellipse axes. The growth conditions and growth behavior of this defect are studied by breaking the overall problem into an elastic stability problem and a fracture problem. Post-buckling solution for the elliptic section is obtained using the Rayleigh-Ritz method while an energy balance criterion based on a self-similar disbond growth governs the fracture. The parameters controlling the growth or arrest of the delamination damage are identified as the fracture energy, disbond depth and elastic properties of the materials from both sides of the delaminating interface. By varying the degree of material anisotropy relative to the loading axis a range in growth behavior was found including stable or unstable crack growth parallel to or normal to the loading axis.

Chai, H.↗
NASA NTRS2013

NASA Tech Briefs, September 2013

Topics include: ISS Ammonia Leak Detection Through X-Ray Fluorescence; A System for Measuring the Sway of the Vehicle Assembly Building; Fast, High-Precision Readout Circuit for Detector Arrays; Victim Simulator for Victim Detection Radar; Hydrometeor Size Distribution Measurements by Imaging the Attenuation of a Laser Spot; Quasi-Linear Circuit; High-Speed, High-Resolution Time-to-Digital Conversion; Li-Ion Battery and Supercapacitor Hybrid Design for Long Extravehicular Activities; Ultrasonic Low-Friction Containment Plate for Thermal and Ultrasonic Stir Weld Processes; High-Powered, Ultrasonically Assisted Thermal Stir Welding; Next-Generation MKIII Lightweight HUT/Hatch Assembly; Centrifugal Sieve for Gravity-Level-Independent Size; Segregation of Granular Materials; Ion Exchange Technology Development in Support of the Urine Processor Assembly; Nickel-Graphite Composite Compliant Interface and/or Hot Shoe Material; UltraSail CubeSat Solar Sail Flight Experiment; Mechanism for Deploying a Long, Thin-Film Antenna From a Rover; Counterflow Regolith Heat Exchanger; Acquisition and Retaining Granular Samples via a Rotating Coring Bit; Very-Low-Cost, Rugged Vacuum System; Medicine Delivery Device With Integrated Sterilization and Detection; FRET-Aptamer Assays for Bone Marker Assessment, C-Telopeptide, Creatinine, and Vitamin D; Multimode Directional Coupler for Utilization of Harmonic Frequencies from TWTAs; Dual-Polarization, Multi-Frequency Antenna Array for use with Hurricane Imaging Radiometer; Complementary Barrier Infrared Detector (CBIRD) Contact Methods; Autonomous Control of Space Nuclear Reactors; High-Power, High-Speed Electro-Optic Pockels Cell Modulator; Covariance Analysis Tool (G-CAT) for Computing Ascent, Descent, and Landing Errors; Enigma Version 12; Micrometeoroid and Orbital Debris (MMOD) Shield Ballistic Limit Analysis Program; Spitzer Telemetry Processing System; Planetary Protection Bioburden Analysis Program; Wing Leading Edge RCC Rapid Response Damage Prediction Tool (IMPACT2); ISSM: Ice Sheet System Model; Automated Loads Analysis System (ATLAS); Integrated Main Propulsion System Performance Reconstruction Process/Models. Phoenix Telemetry Processor; Contact Graph Routing Enhancements Developed in ION for DTN; GFEChutes Lo-Fi; Advanced Strategic and Tactical Relay Request Management for the Mars Relay Operations Service; Software for Generating Troposphere Corrections for InSAR Using GPS and Weather Model Data; Ionospheric Specifications for SAR Interferometry (ISSI); Implementation of a Wavefront-Sensing Algorithm; Sally Ride EarthKAM - Automated Image Geo-Referencing Using Google Earth Web Plug-In; Trade Space Specification Tool (TSST) for Rapid Mission Architecture (Version 1.2); Acoustic Emission Analysis Applet (AEAA) Software; Memory-Efficient Onboard Rock Segmentation; Advanced Multimission Operations System (ATMO); Robot Sequencing and Visualization Program (RSVP); Automating Hyperspectral Data for Rapid Response in Volcanic Emergencies; Raster-Based Approach to Solar Pressure Modeling; Space Images for NASA JPL Android Version; Kinect Engineering with Learning (KEWL); Spacecraft 3D Augmented Reality Mobile App; MPST Software: grl_pef_check; Real-Time Multimission Event Notification System for Mars Relay; SIM_EXPLORE: Software for Directed Exploration of Complex Systems; Mobile Timekeeping Application Built on Reverse-Engineered JPL Infrastructure; Advanced Query and Data Mining Capabilities for MaROS; Jettison Engineering Trajectory Tool; MPST Software: grl_suppdoc; PredGuid+A: Orion Entry Guidance Modified for Aerocapture; Planning Coverage Campaigns for Mission Design and Analysis: CLASP for DESDynl; and Space Place Prime.

Source record↗
NASA NTRS1989

Analysis of notched metal matrix composites under tensile loading

This paper presents techniques based on a three-dimensional finite-element analysis for the analysis of continuous fiber reinforced metal matrix composite. Examples are shown for specific metal matrix composites such as boron/aluminum and silicon-carbide/aluminum. Specimen stress-strain behavior and stress at first fiber failure were predicted for boron/aluminum laminates containing circular holes and crack-like slits. The predictions compared very well with test data for laminates containing 0 deg fibers and reasonably well for (+/-45)2s laminates. Mesh configuration was shown to have an effect on the calculation of stresses local to the notch. The presence of thin interface layers of matrix material had a significant influence on the slit tip stress state, causing sharper stress gradients near the notch. Interface layers reduced the slit-tip fibers stress in a (+/-45)2s silicon-carbide/aluminum laminate but increased them in a (0/90)2s laminate.

Bigelow, C. A.↗
NASA NTRS1988

Analysis of notched metal matrix composites under tension loading

Presented are techniques based on 3-D finite-element analysis for the examination of continuous fiber reinforced metal matrix composites. Examples are shown for specific metal matrix composites such as boron/aluminum and silicon-carbide/aluminum. Specimen stress-strain behavior and stress at first fiber failure were predicted for boron/aluminum laminates containing circular holes and crack-like slits. The predictions compared very well for (+ or - 45) sub 2s laminates. Mesh configuration was shown to have an effect on the calculation of stresses local to the notch. The presence of thin interface layers of matrix material had a significant influence on the slit-tip stress state, causing sharper stress gradients near the notch. Interface layers reduced the slit-tip fibers stresses in a (+ or - 45) sub s silicon-carbide/aluminum laminate but increased them in a (0/90) sub s laminate.

Bigelow, C. A.↗
NASA NTRS1989

An evaluation of the interfacial bond properties between carbon phenolic and glass phenolic composites

The effects of moisture and surface finish on the mechanical and physical properties of the interfacial bond between the carbon/phenolic (C/P) and glass/phenolic (G/P) composite materials are presented. Four flat panel laminates were fabricated using the C/P and G/P materials. Of the four laminates, one panel was fabricated in which the C/P and G/P materials were cured simultaneously. It was identified as the cocure. The remaining laminates were processed with an initial simultaneous cure of the three C/P billets. Two surface finishes, one on each half, were applied to the top surface. Prior to the application and cure of the G/P material to the machined surface of the three C/P panels, each was subjected to the specific environmental conditioning. Types of conditioning included: (1) nominal fabrication environment, (2) a prescribed drying cycle, and (3) a total immersion in water at 160 F. Physical property tests were performed on specimens removed from the C/P materials of each laminate for determination of the specific gravity, residual volatiles and and resin content. Comparisons of results with shuttle solid rocket motor (SRM) nozzle material specifications verified that the materials used in fabricating the laminates met acceptance criteria and were representative of SRM nozzle materials. Mechanical property tests were performed at room temperature on specimens removed from the G/P, the C/P and the interface between the two materials for each laminate. The double-notched shear strength test was used to determine the ultimate interlaminar shear strength. Results indicate no appreciable difference in the C/P material of the four laminates with the exception of the cocure laminate, where 20 percent reduction in the strength was observed. The most significant effect and the ultimate strength was significantly reduced in the wet material. No appreciable variation was noted between the surface finishes in the wet laminate.

Jordan, Kelvin↗
NASA NTRS1989

Weld stresses beyond elastic limit: Materials discontinuity

When welded structures depend on properties beyond the elastic limit to qualify their ultimate safety factor, and weld-parent materials abruptly change at the interface, then stress discontinuity is inevitable. The stress concentration is mildly sensitive to material relative strain hardening and acutely sensitive to applied stress fields. Peak stresses occur on the weld surface, at the interface, and dissipate within a 0.01-inch band. When the stress is intense, the weld will always fracture at the interface. The analysis incorporates a classical mechanics model to more sharply define stress spikes within the bandwidth, and suggests a relative material index and Poisson's ratio related to strain hardening. Implications are discussed which are applicable to industries of high performance structures.

Verderaime, V.↗
NASA NTRS2016

Interface Management for a NASA Flight Project Using Model-Based Systems Engineering (MBSE)

The goal of interface management is to identify, define, control, and verify interfaces; ensure compatibility; provide an efficient system development; be on time and within budget; while meeting stakeholder requirements. This paper will present a successful seven-step approach to interface management used in several NASA flight projects. The seven-step approach using Model Based Systems Engineering will be illustrated by interface examples from the Materials International Space Station Experiment-X (MISSE-X) project. The MISSE-X was being developed as an International Space Station (ISS) external platform for space environmental studies, designed to advance the technology readiness of materials and devices critical for future space exploration. Emphasis will be given to best practices covering key areas such as interface definition, writing good interface requirements, utilizing interface working groups, developing and controlling interface documents, handling interface agreements, the use of shadow documents, the importance of interface requirement ownership, interface verification, and product transition.

Vipavetz, Kevin↗
NASA NTRS1986

Chemical Bonding Technology: Direct Investigation of Interfacial Bonds

This is the third Flat-Plate Solar Array (FSA) Project document reporting on chemical bonding technology for terrestrial photovoltaic (PV) modules. The impetus for this work originated in the late 1970s when PV modules employing silicone encapsulation materials were undergoing delamination during outdoor exposure. At that time, manufacturers were not employing adhesion promoters and, hence, module interfaces in common with the silicone materials were only in physical contact and therefore easily prone to separation if, for example, water were to penetrate to the interfaces. Delamination with silicone materials virtually vanished when adhesion promoters, recommended by silicone manufacturers, were used. The activities related to the direct investigation of chemically bonded interfaces are described.

Koenig, J. L.↗
NASA NTRS2014

Non-Intrusive Sensor for In-Situ Measurement of Recession Rate of Ablative and Eroding Materials

A non-intrusive sensor for in-situ measurement of recession rate of heat shield ablatives. An ultrasonic wave source is carried in the housing. A microphone is also carried in the housing, for collecting the reflected ultrasonic waves from an interface surface of the ablative material. A time phasing control circuit is also included for time-phasing the ultrasonic wave source so that the waves reflected from the interface surface of the ablative material focus on the microphone, to maximize the acoustic pressure detected by the microphone and to mitigate acoustic velocity variation effects through the material through a de-coupling process that involves a software algorithm. A software circuit for computing the location off of which the ultrasonic waves scattered to focus back at the microphone is also included, so that the recession rate of the heat shield ablative may be monitored in real-time through the scan-focus approach.

Papadopoulos, George↗
NASA NTRS2000

Solid-Liquid Interface Characterization Hardware: Advanced Technology Development (ATD)

This ATD has the goal of enabling the integration of three separate measurement techniques to characterize the solid-liquid interface of directionally solidified materials in real-time. Arrays of film-based metal thermocouple elements are under development along with compact Seebeck furnaces suitable for interfacing with separately developed X-ray Transmission Microscopes. Results of applying film arrays to furnace profiling are shown, demonstrating their ability to identify a previously undetected hardware flaw in the development of a second-generation compact furnace. Results of real-time furnace profiling also confirmed that the compact furnace design effectively isolates the temperature profiles in two halves of the furnace, a necessary feature. This isolation had only been inferred previously from the characteristics of Seebeck data reported. Results from a 24-thermocouple array successfully monitoring heating and isothermal cooling of a tin sample are shown. The importance of non-intrusion by the arrays, as well as furnace design, on the profiling of temperature gradients is illustrated with example measurements. Further developments underway for effectively combining all three measurements are assessed in terms of improved x-ray transmission, increased magnification, integral arrays with minimum intrusion, integral scales for velocity measurements and other features being incorporated into the third generation Seebeck furnace under construction.

Peters, Palmer N.↗
NASA NTRS2006

Materials Needs for Future In-Space Propulsion Systems

NASA's In-Space Propulsion Technology Project is developing the next generation of in-space propulsion systems in support of robotic exploration missions throughout the solar system. The propulsion technologies being developed are non-traditional and have stressing materials performance requirements. Earth-storable bipropellant performance is constrained by temperature limitations of the columbium used in the chamber. Iridium/rhenium (Ir/Re) is now available and has been implemented in initial versions of Earth- Storable rockets with specific impulses about 10 seconds higher than columbium rocket chambers. New chamber fabrication methods that improve process and performance of Ir/Re and other promising material systems are needed. The solar sail is a propellantless propulsion system that gains momentum by reflecting sunlight. The sails need to be very large in area (from 10000 sq m up to 62500 sq m) yet be very lightweight in order to achieve adequate accelerations for realistic mission times. Lightweight materials that can be manufactured in thicknesses of less than 1 micron and that are not harmed by the space environment are desired. Blunt Body Aerocapture uses aerodynamic drag to slow an approaching spacecraft and insert it into a science orbit around any planet or moon with an atmosphere. The spacecraft is enclosed by a rigid aeroshell that protects it from the entry heating and aerodynamic environment. Lightweight, high-temperature structural systems, adhesives, insulators, and ablatives are key components for improving aeroshell efficiencies at heating rates of 1000-2000 W/sq cm and beyond. Inflatable decelerators in the forms of ballutes and inflatable aeroshells will use flexible polymeric thin film materials, high temperature fabrics, and structural adhesives. The inflatable systems will be tightly packaged during cruise and will be inflated prior to entry interface at the destination. Materials must maintain strength and flexibility while packaged at cold temperatures (-100 C) for up to 10 years and then withstand the high temperatures (500 C) encountered during aerocapture.

Johnson, Les↗
NASA NTRS2008

Materials Needs for Future In-space Propulsion Systems

NASA is developing the next generation of in-space propulsion systems in support of robotic exploration missions throughout the solar system. The propulsion technologies being developed are non-traditional and have stressing materials performance requirements. (Chemical Propulsion) Earth-storable chemical bipropellant performance is constrained by temperature limitations of the columbium used in the chamber. Iridium/rhenium (Ir/Re) is now available and has been implemented in initial versions of Earth-Storable rockets with specific impulses (Isp) about 10 seconds higher than columbium rocket chambers. New chamber fabrication methods that improve process and performance of Ir/Re and other promising material systems are needed. (Solar Sail Propulsion) The solar sail is a propellantless propulsion system that gains momentum by reflecting sunlight. The sails need to be very large in area (from 10000 m2 up to 62500 m2) yet be very lightweight in order to achieve adequate accelerations for realistic mission times. Lightweight materials that can be manufactured in thicknesses of less than 1 micron and that are not harmed by the space environment are desired. (Aerocapture) Blunt Body Aerocapture uses aerodynamic drag to slow an approaching spacecraft and insert it into a science orbit around any planet or moon with an atmosphere. The spacecraft is enclosed by a rigid aeroshell that protects it from the entry heating and aerodynamic environment. Lightweight, high-temperature structural systems, adhesives, insulators, and ablatives are key components for improving aeroshell efficiencies at heating rates of 1000-2000 W/cu cm and beyond. Inflatable decelerators in the forms of ballutes and inflatable aeroshells will use flexible polymeric thin film materials, high temperature fabrics, and structural adhesives. The inflatable systems will be tightly packaged during cruise and will be inflated prior to entry interface at the destination. Materials must maintain strength and flexibility while packaged at cold temperatures (_100oC) for up to 10 years and then withstand the high temperatures (500oC) encountered during aerocapture. The presentation will describe the status of each propulsion technology and summarize the materials needed for their implementation.

Johnson, Charles Les↗
NASA NTRS1973

Materials sciences research

Research projects involving materials research conducted by various international test facilities are reported. Much of the materials research is classified in the following areas: (1) acousto-optic, acousto-electric, and ultrasonic research, (2) research for elucidating transport phenomena in well characterized oxides, (3) research in semiconductor materials and semiconductor devices, (4) the study of interfaces and interfacial phenomena, and (5) materials research relevant to natural resources. Descriptions of the individual research programs are listed alphabetically by the name of the author and show all personnel involved, resulting publications, and associated meeting speeches.

Source record↗
NASA NTRS1987

Interface roughness effect on stresses in ceramic coatings

This paper presents an analysis of the interface stress in plasma-sprayed zirconia coatings. The stress distributions along smooth and rough interfaces were calculated for perfectly bonded materials. The effect of mechanial interlock along the interface was also calculated. The interface stresses for noninterlocking interfaces were consistently higher; the interlocking interfaces showed high stresses in small regions only.

Mullen, Robert L.↗
NASA NTRS1991

Adhesion and abrasion of surface materials in the Venusian aeolian environment

In laboratory simulations of the Venusian environment, rock and mineral 'target' surfaces struck by aeolian particles develop a thin layer of accretionary material derived from the particles' attrition debris. Accretion may be (in part) a manifestation of 'cold welding', a process well known in engineering, where bonding occurs between metals at a tribological interface. Accretion on geological materials was found to occur at all Venusian surface temperatures and for all types of materials tested. First-order variations in the amount deposited by particles are related to relative attrition susceptibilities. Second-order variations relate to properties of the particle-target interface. Variations in accretion volume are apparently independent of mineral chemistry and are only weakly dependent on crystallography. The results suggest that accretion should be a fairly universal phenomenon in areas of Venus subject to aeolian activity.

Marshall, John R.↗
NASA NTRS1972

Collocated interfacial stress intensity factors for finite bi-material plates.

This paper deals with elastic stress intensity factors associated with stress fields near partially debonded interfaces in finite, bi-material plates. Bi-material stress intensity factors K1 and K2 are not associated, respectively, with symmetric and skew-symmetric loading and are functions of an arbitrary length parameter. Any fracture condition involving bi-material stress intensity factors must be independent of the arbitrary length parameter and must be consistent with experiment. We define a new parameter called the interfacial stress intensity factor which satisfies the former condition. A truncated Williams power series stress function for stresses in a cracked bi-material plate, as modified by Sih and Rice, is used with a modified boundary collocation procedure to generate interfacial stress intensity factors for finite bi-material plates.

Sawyer, S. G.↗
NASA NTRSDate not supplied

Mechanisms of Interfacial Mixing in the Blown Powder Deposition of Inconel 625 to Copper Alloy for Liquid Rocket Engine Applications

There is an increasing need for functional materials to support high heat flux applications and optimize weight by using bimetallic additive manufacturing (AM). While one promising fabrication technology is the use of blown powder directed energy deposition (DED) AM, challenges remain with bi-metallic combinations. Prominent among these challenges is the need to understand mixing of materials at the bimetallic interface for forming stronger, more durable and reliable joints to extend the versatility of AM into critical applications. One application is the manufacturing of combustion chambers with copper-alloy liners and Superalloy structural jackets. In this application, material combinations are selected for effective heat dissipation, using copper, and retention of strength at high temperatures using Inconel 625. Currently, the dominant problem with this configuration is the highly variable strength of the interface and its correlation with deposition parameters. In this study, samples were fabricated at several vendors with Inconel 625 deposited onto wrought C-18150 (Cu-Cr-Zr) to form a bimetallic interface. Characterization of the interfaces were achieved through optical and electron microscopy, mechanical testing of mini tensile specimens, and electron dispersion spectroscopy to understand diffusion and bulk mixing behaviors at the joint. A theoretical framework was constructed in the context of solidification and mixing mechanisms to explain the resulting differences in the interface. This qualitative approach utilized a fluid dynamics perspective to sum the order of magnitudes of the various acting forces on the weld pool during deposition to predict convection trends based off known parameters. The predicted trends for each vendor are compared to obtain a better understanding of how mixing in the molten pool varied based on deposition parameters.

Additive Manufacturing↗
NASA NTRS1999

Preliminary Study of a Pull Plug Friction Weld

A pull plug friction weld, simply defined, comprises inserting a rotating cone-shaped cylinder into a somewhat cone-shaped hole in a plate. The rotating plug makes contact with the edge of the plate and the resulting friction generates heat. The temperature of the plate material eventually reaches a magnitude that will cause the plate material at the edge of the hole to flow. This can be termed a temperature dependent plastic flow. The rotation of the plug is terminated, additional pressure is applied and the metal at the interface of the two materials cools and welding occurs. This preliminary study addresses only three aspects of a complete analysis that is multi-faceted. The transient temperature distribution for different pull plug configurations has been studied in some detail even though the initial conditions and boundary conditions may still be deemed tentative. The stress distribution within the pull plug caused by the heating pressure was studied along with a preliminary analysis of the thermoelastic stress distribution caused by friction heating. There are no definitive results for the stress analysis. Additional study will be required.

Buchanan, George R.↗