Tech Briefs

Systems, Apparatuses, and Methods for Using Durable Adhesively Bonded Joints for Sandwich Structures

A preform insert enables redundant bond lines and mass efficient load transfer across the joint.NASA'S Langley Research Center has developed a new adhesively bonded joint concept for curved and flat panel sandwich architectures. A woven preform, inserted into the seam between sandwich panels, provides a larger total bonding area and multiple load paths for an improved distribution of load through the joint. NASA is able to create structures by joining sections of sandwich panels or curved shells. The new joint provides more durable load transfer and redundant load paths compared to current state-of-the-art adhesively bonded strap joints.

Posted in: Briefs, Manufacturing & Prototyping, Product development, Joining, Adhesives and sealants


Preliminary Design of a Cryogenic Hydrogen Radiation Shield for Human Spaceflight

Liquid hydrogen is the most mass-efficient radiation shielding material.Human susceptibility to the harsh space radiation environment has been identified as a major hurdle for exploration beyond low-Earth orbit (LEO). High-energy protons and nuclei ions from Solar Energetic Particles (SEPs) and Galactic Cosmic Rays (GCRs) can result in radiation doses that are dangerous to astronaut health and even survivability if the astronauts are not adequately shielded. These high-energy particles also cause significant amounts of secondary radiation when they impinge on the spacecraft structure. Hydrogen or hydrogen-rich materials are ideal materials for radiation shielding because hydrogen does not easily break down to form a secondary radiation source.

Posted in: Briefs, Manufacturing & Prototyping, Hydrogen storage, Human factors, Radiation protection, Spacecraft


Methods of Making and Using Tubular Solid Oxide Fuel Cells (SOFCs)

SOFCs have applications in vehicle auxiliary power units, and emergency backup power for telecom and cable repeaters.Human-occupied vehicles and autonomous vehicles such as rovers and landers may benefit from the fuel flexibility and high energy density of solid oxide fuel cells (SOFCs), compared to batteries and polymer electrolyte membrane (PEM) systems. Fuel systems greater than 1 kW are traditionally planar and exhibit high volumetric power density; however, due to large sealing areas, they have poor cycling characteristics. Recently, 250 cycles on a Tubular SOFC (T-SOFC) system (Protonex Technology Corp.) was demonstrated. Hot zones designed around T-SOFCs have a lower packing density, but significantly better cycle life and start times, making them an ideal solution. By increasing the power density of T-SOFCs, overall hot zone and system volumetric power densities can be greatly improved. Extending the methodology of freeze-casting to T-SOFCs will provide a system with the micro-structural advantages of their planar counterpart, but with the rapid thermal cycling capacity of traditional extruded SOFCs.

Posted in: Briefs, Manufacturing & Prototyping, Fuel cells, On-board energy sources, Product development


Tool Designs for Friction Stir Welding

This repeatable, environmentally friendly, cost-effective weld method is able to weld traditionally “unweldable” alloys.Friction stir welding (FSW) is a solidstate welding process that shows promise in the aerospace industry. A new system of experimentation has been used to quickly make and screen new tool designs. After conducting a literature review, friction stir tools were designed to optimize material flow around the tool.

Posted in: Briefs, Manufacturing & Prototyping, Design processes, Technical review, Manufacturing equipment and machinery, Welding


Novel Electrochemical Cell Designs for Simultaneous Production of Methane and Oxygen via the Electrolysis of Carbon Dioxide and Water

The two-chamber cell design allows electrolysis of water and carbon dioxide in separate chambers to minimize production of unwanted products.NASA has investigated and demonstrated the simultaneous production of methane (CH4) and oxygen (O2) via the electrolysis of carbon dioxide (CO2) and water (H2O) in one or more ionic liquids (ILs). In order to improve the likelihood of methane and oxygen production, and to reduce the likelihood of unwanted side-product formation, several innovative approaches were investigated. Research has shown thousands of options for ionic liquids that can be used in the electrochemical process; however, care must be taken to choose an ionic liquid that has high carbon dioxide solubility, limited change in viscosity due to carbon dioxide absorption, and chemical stability during the electrochemical process.

Posted in: Briefs, Manufacturing & Prototyping, Carbon dioxide, Water, Methane, Research and development, Production, Oxygen


Eddy Current System and Method for Crack Detection

This probe can identify outer surface damage from within the interior of installed hardware.NASA's Langley Research Center has developed a new eddy current inspection device that probes for cracks in parts of metal structures that are often inaccessible without extensive disassembly. The probe is specially designed for insertion into the cavity of a part to inspect the surrounding structure in an outward direction. For example, the probe may be held inside a large, thick tube and pointed outward to inspect the outer diameter of the tube. NASA used the probe to test for stress corrosion cracking in the relief radius of Space Shuttle thrusters without having to dismantle the hardware, reducing inspection time while ensuring the health of the structure. NASA Langley is seeking organizations that would like to license the probe to test for cracks in rocket thrusters and other metallic structures with hard-to-reach inspection areas.

Posted in: Briefs, Sensors, Sensors and actuators, Fatigue, Metals, Inspections


Metal Stamping Design Guidelines

Metal Stamping provides an economical way to produce quantities of parts that can possess many qualities, including strength, durability, wear resistance, good conductive properties, and stability. In this paper, we are sharing some ideas that can help you design a part that optimizes all the features that the metal stamping process offers.

Posted in: Briefs, TSP, Aeronautics, Manufacturing & Prototyping, Materials, Mechanical Components, Design processes, Stamping, Metals, Parts


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