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Technical Paper

A Fast Running Loading Methodology for Ground Vehicle Underbody Blast Events

2018-04-03
2018-01-0620
A full-system, end-to-end blast modeling and simulation of vehicle underbody buried blast events typically includes detailed modeling of soil, high explosive (HE) charge and air. The complex computations involved in these simulations take days to just capture the initial 50-millisecond blast-off phase, and in some cases, even weeks. The single most intricate step in the buried blast event simulation is in the modeling of the explosive loading on the underbody structure from the blast products; it is also one of the most computationally expensive steps of the simulation. Therefore, there is significant interest in the modeling and simulation community to develop various methodologies for fast running tools to run full simulation events in quicker turnarounds of time.
Standard

Automotive Gear Lubricants for Commercial and Military Use

2022-05-20
CURRENT
J2360_202205
The gear lubricants covered by this standard exceed American Petroleum Institute (API) Service Classification API GL-5 and are intended for hypoid-type, automotive gear units, operating under conditions of high-speed/shock load and low-speed/high-torque. These lubricants may be appropriate for other gear applications where the position of the shafts relative to each other and the type of gear flank contact involve a large percentage of sliding contact. Such applications typically require extreme pressure (EP) additives to prevent the adhesion and subsequent tearing away of material from the loaded gear flanks. These lubricants are not appropriate for the lubrication of worm gears. Appendix A is a mandatory part of this standard. The information contained in Appendix A is intended for the demonstration of compliance with the requirements of this standard and for listing on the Qualified Products List (QPL) administered by the Lubricant Review Institute (LRI).
Standard

Automotive Gear Lubricants for Commercial and Military Use

2021-01-27
HISTORICAL
J2360_202101
The gear lubricants covered by this standard exceed American Petroleum Institute (API) Service Classification API GL-5 and are intended for hypoid-type, automotive gear units, operating under conditions of high-speed/shock load and low-speed/high-torque. These lubricants may be appropriate for other gear applications where the position of the shafts relative to each other and the type of gear flank contact involve a large percentage of sliding contact. Such applications typically require extreme pressure (EP) additives to prevent the adhesion and subsequent tearing away of material from the loaded gear flanks. These lubricants are not appropriate for the lubrication of worm gears. Appendix A is a mandatory part of this standard. The information contained in Appendix A is intended for the demonstration of compliance with the requirements of this standard and for listing on the Qualified Products List (QPL) administered by the Lubricant Review Institute (LRI).
Technical Paper

Computing Remaining Fatigue Life Under Incrementally Updated Loading Histories

2018-04-03
2018-01-0623
After manufacture, every military vehicle experiences a unique history of dynamic loads, depending on loads carried, missions completed, etc. Damage accumulates in vehicle structures and components accordingly, leading eventually to failures that can be difficult to anticipate, and to unpredictable consequences for mission objectives. The advent of simulation-based fatigue life prediction tools opens a path to Digital Twin based solutions for tracking damage, and for gaining control over vehicle reliability. An incremental damage updating feature has now been implemented in the Endurica CL fatigue solver with the aim of supporting such applications for elastomer components. The incremental updating feature is demonstrated via the example of a simple transmission mount component. The damage state of the mount is computed as it progresses towards failure under a series of typical loading histories.
Book

Counterfeit Parts and Their Impact on the Supply Chain, Second Edition

2018-11-15
Why should the supply chain be concerned if their buyers or subcontractors are purchasing counterfeit electronic parts or if their products contain counterfeit electronic parts? If these parts end up in items that are safety critical and security-risk sensitive such as aviation, space, and defense products, whole secure systems can be comprised. As organizations have become aware of counterfeit parts, one of their responses may be to test upon acceptance or prior to receipt. But testing alone may not detect all counterfeits. Possible sources of counterfeits include products that did not meet quality control requirements and were not destroyed, overruns sold into the market place, unauthorized production shifts, theft, and e-waste. The counterfeited electronic part ends up in the supply chain when ordered by an unsuspecting buyer, who does not confirm the originating source of the part.
Technical Paper

Decomposition and Coordination to Support Tradespace Analysis for Ground Vehicle Systems

2022-03-29
2022-01-0370
Tradespace analysis is used to define the characteristics of the solution space for a vehicle design problem enabling decision-makers (DMs) to evaluate the risk-benefit posture of a vehicle design program. The tradespace itself is defined by a set of functional objectives defined by vehicle simulations and evaluating the performance of individual design solutions that are modeled by a set of input variables. Of special interest are efficient design solutions because their perfomance is Pareto meaning that none of their functional objective values can be improved without decaying the value of another objective. The functional objectives are derived from a combination of simulations to determine vehicle performance metrics and direct calculations using vehicle characteristics. The vehicle characteristics represent vendor specifications of vehicle subsystems representing various technologies.
Book

Fundamentals of Geometric Dimensioning and Tolerancing 2018: Using Critical Thinking Skills, Revised Edition

2021-12-02
The Fundamentals of Geometric Dimensioning and Tolerancing 2018 Using Critical Thinking Skills by Alex Krulikowski reflects the technical content found in the latest release of the ASME Y14.5-2018 Standard. This book includes several key features that aid in the understanding of geometric tolerancing. Each of the textbook's 26 chapters focuses on a major topic that must be mastered to be fluent in the fundamentals of GD&T. Each topic includes a goal that is defined and supported by a set of performance objectives that include real-world examples, verification principles and methods, and chapter summaries. There are more than 260 performance objectives that describe specific, observable, measurable actions that the student must accomplish to demonstrate mastery of each goal. Learning is reinforced by completing three types of exercise problems, along with critical thinking questions that promote application of GD&T on the job.
Journal Article

Infrared Signature of Fixed and Variable Area C-D Nozzle of Aircraft Engine

2023-01-02
Abstract The use of converging-diverging (C-D) variable area nozzle (VAN) in military aeroengines is now common, as it can give optimal expansion and control over engine back pressure, for a wide range of engine operations. At higher main combustion temperatures (desired for supercruise), an increase in the nozzle expansion ratio is needed for optimum performance. But changes in the nozzle throat and exit areas affect the visibility of engine hot parts as the diverging section of the nozzle is visible for a full range of view angle from the rear aspect. The solid angle subtended by engine hot parts varies with change in visibility, which affects the aircraft infrared (IR) signature from the rear aspect. This study compares the performances of fixed and variable area nozzles (FAN and VAN) in terms of engine thrust and IR signature of the engine exhaust system in the boresight for the same increase in combustion temperature.
Article

Quality management experts provide guidance on AS9100 standard

2021-11-04
Quality management professionals across the global aerospace and defense community are convening for one hour – Wednesday, October 27th, starting at 10 am Pacific Daylight Time (PDT) – to discuss the AS9100 international standard. Register to take part in the free AeroTech webinar, hosted by SAE International and Tektronix, designed to help manufacturers, contractors, and subcontractors throughout the global aviation, space, and defense supply chain keep pace with and meet the requirements of AS9100 international quality management system standard.
Standard

Requirements for Aviation, Space, and Defense Auditor Training, Development, Competence, and Authentication

2020-11-11
CURRENT
AS9104/3A
This document defines the minimum requirements for auditors, CBs, Auditor Authentication Bodies (AABs), Training Provider Approval Bodies (TPABs), and Training Providers (TPs) who participate in the IAQG Industry Controlled Other Party (ICOP) scheme. The requirements in this standard supplement those defined within the 9104/1, 9104/2, ISO/IEC 17021-1, and ISO/IEC 17021-3 standards. Data protection for the parties subject to this document and other relevant requirements of the ICOP scheme are managed via bi-lateral contracts between the joint controllers of the data.
Standard

S400 Copper Media Interface Characteristics Over Extended Distances

2019-07-09
CURRENT
AS5643/1A
This SAE Aerospace Standard (AS) establishes guidelines for the use of IEEE-1394-2008 Beta (formerly IEEE-1394b) as a data bus network in military and aerospace vehicles. It encompasses the data bus cable and its interface electronics for a system utilizing S400 over copper medium over extended lengths. This document contains extensions/restrictions to “off-the-shelf” IEEE-1394 standards, and assumes that the reader already has a working knowledge of IEEE-1394. This document does not identify specific environmental requirements (electromagnetic compatibility, temperature, vibration, etc.); such requirements will be vehicle-specific and even LRU-specific. However, the hardware requirements and examples contained herein do address many of the environmental conditions that military and aerospace vehicles may experience. One should refer to the appropriate sections of MIL-STD-461E for their particular LRU, and utilize handbooks such as MIL-HDBK-454A and MIL-HDBK-5400 for guidance.
Standard

Standard Practice for Human Systems Integration

2019-02-08
HISTORICAL
SAE6906
This Human Systems Integration (HSI) Standard Practice identifies the Department of Defense (DoD) approach to conducting HSI programs as part of procurement activities. This Standard covers HSI processes throughout design, development, test, production, use, and disposal. Depending on contract phase and/or complexity of the program, tailoring should be applied. The scope of this standard includes prime and subcontractor HSI activities; it does not include Government HSI activities, which are covered in the DoD HSI Handbook. HSI programs should use the latest version of standards and handbooks listed below, unless a particular revision is specifically cited in the contract.
Magazine

Tech Briefs: May 2018

2018-05-01
New Technologies Tackle UAV Challenges Robotic Applique Kits Leverage Existing Assets Educating UGVs Implementing AI Advancements in Thermal Image Training Data Sets Protecting Critical Data on Unmanned Underwater Platforms Advancements Made to the Wingman Software-in-the-Loop (SIL) Simulation: How to Operate the SIL New features include the creation of virtual environments that match real-world gunnery test courses. Soldier-Robot Team Communication: An Investigation of Exogenous Orienting Visual Display Cues and Robot Reporting Preferences The effective use of robots to conduct dangerous missions depends on accurate man-machine communications. Soft Robotic Fish Swims Alongside Real Ones in Coral Reefs GPS Enabled Semi-Autonomous Robot Combining GPS signals with acoustic and encoder data gives a robot the ability to determine its location and orientation within a reference frame.
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