Tech Briefs

Microstructural and Mechanical Characterization of 2-D and 3-D SiC/SiNC Ceramic-Matrix Composites

The purpose of this endeavor was to investigate the effect of 3-D weave architecture on PIP-processed ceramic-matrix composites (CMC). Microstructural studies were performed to document the resulting microstructure and mechanical testing was performed to determine the high-temperature durability of the five different variants of SiC/SiNC CMC investigated.

Posted in: Briefs, Aerospace
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Evaluation of Peel Ply Surface Preparation of Composite Surfaces for Secondary Bonding

Lightweight composite structures offer significant long-term cost-saving opportunities for the U.S. Army as replacements for traditional metal structures. However, high-strength economical bonding processes must be developed to join composites in order for them to be viable replacements. The Army is exploring approaches, also under evaluation in the commercial aerospace industry, to reduce the process steps associated with composite bonding.

Posted in: Briefs, Aerospace
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Enhanced Contacts for Inverted Metamorphic Multi-Junction Solar Cells Using Carbon Nanotube Metal Matrix Composites

In order to address issues related to mechanical and vibrational stresses that are commonly experienced in mounting, launch, and deployment of spacecraft, metal matrix composite (MMC) electrodes were fabricated with carbon nanotubes (CNTs) as reinforcement. The research plans were centered on first developing and selecting appropriate processes for fabricating CNT-MMCs based on characterization of their material properties, followed by optimizing MMC designs based on electrical testing under stress. Efforts in the program were also directed toward implementing the CNT-MMCs into solar cell device processing in a process compatible with standard clean room procedures.

Posted in: Briefs, Aerospace
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Reusable Rapid Prototyped Blunt-Impact Simulator

Rapid prototyping (RP) is the term most commonly used to describe additive manufacturing technologies. An additive manufacturing technology is any manufacturing process that fabricates a part by adding one layer of material at a time, one on top of the other, to produce detailed 3-D geometries directly from 3-D computer-aided design (CAD) models.

Posted in: Briefs, Aerospace
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Maintaining Enterprise Resiliency Via Kaleidoscopic Adaption and Transformation of Software Services (MEERKATS)

This research investigates a new vision for increasing the resilience of computing clouds by elevating continuous change, evolution, and misinformation as first-rate design principles of the cloud's infrastructure. The work is motivated by the fact that today's clouds are very static, uniform, and predictable, allowing attackers who identify a vulnerability in one of the services or infrastructure components to spread their effect to other, mission-critical services. The goal is to integrate into clouds a new level of unpredictability for both their services and data so as to both impede an adversary's ability to achieve an initial system compromise and, if a compromise occurs, to detect, disrupt, and/or otherwise impede their ability to exploit this success.

Posted in: Briefs, Aerospace
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Burner Rig Testing of A500® C/SiC

There is growing interest in developing, testing, and deploying ceramic-matrix composites (CMCs) into commercial and military aerospace gas turbine engines due to their durability under extreme conditions and weight-savings potential. For military applications, the focus is on the afterburning section of the turbine engine, including the flameholder, augmentor liner, and both the convergent and divergent segments of the exhaust nozzle. These are demanding applications because of the high temperatures and rapid thermal cycles.

Posted in: Briefs, Aerospace, Composites, Materials, Instrumentation, Measuring Instruments, Monitoring, Test & Measurement
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Space Debris Orbit and Attitude Prediction for Enhanced and Efficient Space Situational Awareness

This research deals with the problem of modelling the orbit and attitude motion of uncontrolled manmade objects in orbit about the Earth, which tumble due to the natural influences of the near-Earth space environment. A mathematical, physics-based and computational approach is taken to model the forces and torques that drive the orbit and attitude evolution of such objects. The main influence modelled is solar radiation pressure (SRP), which is the interaction of solar electromagnetic radiation with the surface of an object, leading to both forces and torques that influence the orbital and attitude motion. Other influences, such as the gravitational field of the Earth, are also modelled.

Posted in: Briefs, Aerospace
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