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Technical Paper

Development of the Next Generation Flexible Tooling System

2019-03-19
2019-01-1362
Flexible Tooling Systems have been developed as a reconfigurable part support system to enable trimming of multiple part geometries utilizing a single router or waterjet. The driver for this development has been improved part quality, elimination of ergonomic issues associated with manually trimming, and the elimination of cost for part number specific hard tooling and the associated cost for manufacturing, maintenance, and storage. This paper will briefly trace the evolution of aerospace parts trimming history. The remainder of the report will focus on the technical objectives associated with the development of the Next Generation Flexible Tooling System, how they were achieved including the process for validation of each support location in aircraft coordinates. This system is designed to increase part holding accuracy with specific support location validation, and significantly reduce system maintenance costs in wet or dry environments.
Technical Paper

Theoretical Modeling of the Mechanical Degradation of Polymer Composites due to Moisture/Water Absorption and Damage Progression

2019-03-19
2019-01-1376
The moisture/water absorption and microvoids/cracks progression are two well-understood mechanisms that have significant degradation effects on the mechanical properties/behaviors of the polymer-based composites. To theoretically investigate the effects of above two mechanisms, we develop a simple fiber reinforced polymer composites model by employing the internal state variable (ISV) theory. The water content and the anisotropically distributed damage of the composites are considered as two ISVs (the water content is described by a scalar variable and the damage is defined as a second order tensor) whose histories are governed by two specific physically-based evolution equations. The proposed model can be easily cast into a general theoretical framework to capture more polymer composites behaviors such as viscoelasticity, viscoplasticity and the thermal effect.
Magazine

Tech Briefs: April 2018

2018-04-01
Laser Detecting Systems Enhancing Survivability and Lethality on the Battlefield Designing With Plastics for Military Equipment Engine Air-Brakes Paving the Way to Quieter Aircraft Nett Warrior Enhancing Battlefield Connectivity and Communications XPONENTIAL 2018 - An AUVSI Experience Communications in Space: A Deep Subject First Air-Worthy Metal-Printed RF Filter Ready for Takeoff Validation of Automated Prediction of Blood Product Needs Algorithm Processing Continuous Non-Invasive Vital Signs Streams (ONPOINT4) Using a combination of non-invasive sensors, advanced algorithms, and instruments built for combat medics could reduce hemorrhaging and improve survival rates. Calculation of Weapon Platform Attitude and Cant Using Available Sensor Feedback Successful development of mobile weapon systems must incorporate operation on sloped terrain.
Book

The History of Metals in America

2018-01-01
The History of Metals in America chronicles the development of metals as both an industrial activity and a science. Progress involving structural metals made possible the air, land, sea, and space travel of today, skyscrapers reaching over 100 stories high, and many other engineering accomplishments that continue to shape modern society. This lively book takes the reader on a fascinating journey through the evolution of metals and metallurgy from the beginning of iron production in colonial times with the first iron plant in 1645 to the prevailing metals of the 21st century. Each chapter describes the development of a metal or series of metal alloys, industry growth, and modern uses in manufacturing. It includes chapters on cast iron, wrought iron, alloy steels, tool steels, stainless steels, nickel-base superalloys, aluminum, and titanium. Other chapters cover the science of metals as it developed from 1890 to 1950 and the biographies of the pioneers of metals research.
White Paper

Electric Flight Technology

2017-10-25
WP-0002
The environmental impact of hydrocarbon-burning aircraft, both from the perspective of gas emissions and that of noise, is one of the main motivations for the move to electric propulsion. The added benefit from this shift to electric propulsion is that it has resulted in lowering the costs of electrical components such as motors, power electronic (PE) circuits, and batteries that are essential to this technology. This white paper seeks to explore the history, architecture, electrical components, and future trends of electric flight technology.
Journal Article

Time-Varying Loads of Co-Axial Rotor Blade Crossings

2017-09-19
2017-01-2024
The blade crossing event of a coaxial counter-rotating rotor is a potential source of noise and impulsive blade loads. Blade crossings occur many times during each rotor revolution. In previous research by the authors, this phenomenon was analyzed by simulating two airfoils passing each other at specified speeds and vertical separation distances, using the compressible Navier-Stokes solver OVERFLOW. The simulations explored mutual aerodynamic interactions associated with thickness, circulation, and compressibility effects. Results revealed the complex nature of the aerodynamic impulses generated by upper/lower airfoil interactions. In this paper, the coaxial rotor system is simulated using two trains of airfoils, vertically offset, and traveling in opposite directions. The simulation represents multiple blade crossings in a rotor revolution by specifying horizontal distances between each airfoil in the train based on the circumferential distance between blade tips.
Standard

Oxygen Cylinder Quality, Serviceability, Maintenance Transfilling and Marking

2017-05-19
HISTORICAL
AIR1059E
This document provides guidance concerning the maintenance and serviceability of oxygen cylinders beginning with the quality of oxygen that is required, supplemental oxygen information, handling and cleaning procedures, transfilling and marking of serviced oxygen assemblies. This document attempts to outline in a logical sequence oxygen quality, serviceability, and maintenance of oxygen cylinders. Content of this document can also be used for refilling of oxygen cylinder while installed on aircraft, directly or through an intermediate charging port.
Standard

UxS Control Segment (UCS) Architecture: UCTRACE

2016-12-20
CURRENT
AIR6519
The Use Case Trace (UCTRACE) is SAE publication AIR6519 of the Department of Defense Unmanned Control Segment (UCS) Architecture. This document is the SAE publication of the Department of Defense UAS Control Segment (UCS) Architecture: Use Case Trace (UCTRACE) Version 3.4(PR) approved for Distribution A public release 15.S-1859. This information is produced from a script run against the System Use Case Model contained in the UCS Architecture Model AS6518-MODEL.eap configuration item. The System Use Case Model includes, at its lowest level of elaboration, use cases Level 2/3 (L2/L3) that describe specific scenarios of message exchanges between Actors and internal system Participants via ServiceInterfaces. These message exchanges provide a way to create detailed traces that answer the question: “What UCS service interfaces must my components implement to satisfy functional requirements represented by a given Level 2/3 UCS use case?”
Standard

Unmanned Systems (UxS) Control Segment (UCS) Architecture: UCS Architecture Model

2016-12-20
HISTORICAL
AS6518
This brief User Guide recaps the content of the AS6518 UCS Architectural Model described in detail in AS6512 UCS Architecture: Architecture Description. The purpose of the UCS Architecture Model is to provide the authoritative source for other models and products within the UCS Architecture as shown in the AS6512 UCS Architecture: Architecture Description.
Technical Paper

DO-254/ED-80 - An Application Guidelines to Redesign/Re-Engineering Airborne Electronic Hardware

2016-09-20
2016-01-2039
Avionics industry is moving towards fly-by wire aircrafts with less reliance on mechanical systems leading to increase in the complexity of in-flight hardware elements. RTCA/DO-254 and EUROCAE ED-80 plays a vital role in the design assurance of airborne electronic hardware. RTCA/ DO-254 and EUROCAE ED-80 are the industry standards for Design Assurance Guidance for Airborne Electronic Hardware. The two different agencies FAA and EU regulate and apply this design assurance guidance to the regulatory law in CFR and EASA CS respectively. This paper discusses the need for DO-254 /ED-80 certification in Aerospace industry, the advantages and benefits to the avionics manufacturers. The paper presents the study made on similarities and differences between DO-254/ED-80.
Standard

Ball-On-Cylinder (BOC) Aircraft Turbine Fuel Lubricity Tester

2016-07-26
CURRENT
AIR1794B
This metric SAE Aerospace Information Report (AIR) details a ball-on-cylinder (BOC) test device and specifies a method of rating the relative lubricity of aviation turbine fuel samples. The BOC produces a wear scar on a stationary steel ball by forcing it with a fixed load against a fuel wetted steel test ring in a controlled atmosphere. The test ring is rotated at a fixed speed so its surface is wetted by a momentary exposure to the fluid under test. The size of the wear scar is a measure of the test fluid lubricity and provides a basis for predicting friction or wear problems.
Standard

CDIF Integrated Meta-model - State/Event Model Subject Area

2016-06-16
CURRENT
EIAIS116
The CDIF Family of Standards is primarily designed to be used as a description of a mechanism for transferring information between CASE tools. It facilitates a successful transfer when the authors of the importing and exporting tools have nothing in common except an agreement to conform to CDIF. The language that is defined for the Transfer Format also has applicability as a general language for Import/Export from repositories. The CDIF Integrated Meta-model defined for CASE also has applicability as the basis of standard definitions for use in repositories. The standards that form the complete family of CDIF Standards are documented in EIA/IS-106 CDIF - CASE Data Interchange Format - Overview. These standards cover the overall framework, the transfer format and the CDIF Integrated Meta-model. The diagram in Figure 1 depicts the various standards that comprise the CDIF Family of Standards. The shaded box depicts this standard and its position in the CDIF Family of Standards.
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