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Standard

Air Cycle Air Conditioning Systems for Air Vehicles

2019-08-20
CURRENT
AS4073B
This SAE Aerospace Standard (AS) defines the requirements for air cycle air conditioning systems used on military air vehicles for cooling, heating, ventilation, and moisture and contamination control. General recommendations for an air conditioning system, which may include an air cycle system as a cooling source, are included in MIL-E-18927E and JSSG-2009. Air cycle air conditioning systems include those components which condition high temperature and high pressure air for delivery to occupied and equipment compartments and to electrical and electronic equipment. This document is applicable to open and closed loop air cycle systems. Definitions are contained in Section 5 of this document.
Journal Article

Numerical Analysis of Blast Protection Improvement of an Armored Vehicle Cab by Composite Armors and Anti-Shock Seats

2018-12-05
Abstract The objective of this article is to evaluate the effects of different blast protective modules to military vehicle structures and occupants. The dynamic responses of the V-shape integral basic armor, the add-on honeycomb sandwich structure module, and the anti-shock seat-dummy system were simulated and analyzed. The improvements of occupant survivability by different protective modules were compared using occupant injury criteria. The integral armored cab can maintain the integrity of the cab body structure. The add-on honeycomb sandwich armor reduces the peak structural deformation and velocity of the cab floor by 34.9% and 47.4%, respectively, compared with the cab with integral armors only. The integral armored cab with the anti-shock seat or the honeycomb sandwich structures reduces the occupant shock responses below the injury criteria. For different blast threat intensities, the selection of appropriate protective modules can meet protection requirements.
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.
Standard

Perspectives on Integrating Structural Health Monitoring Systems into Fixed-Wing Military Aircraft

2019-09-18
CURRENT
AIR6245
This SAE Aerospace Information Report (AIR) is prepared for stakeholders seeking information about the evolution, integration, and approval of SHM technologies for military aircraft systems. The report provides this information in the form of (a) two military organizations’ perspectives on requirements, and (b) general SHM challenges and industry perspectives. The report only provides information to generate awarness of prespectives for military aircraft and, hence, assists those who are involved in developing SHM systems understanding the broad range of regulations, requirements, and standards published by military organizations that are available in the public domain from the military organizations.
Journal Article

Nonlinear Multi-Fidelity Bayesian Optimization: An Application in the Design of Blast Mitigating Structures

2022-03-29
2022-01-0790
A common scenario in engineering design is the availability of several black-box functions that describe an event with different levels of accuracy and evaluation cost. Solely employing the highest fidelity, often the most expensive, black-box function leads to lengthy and costly design cycles. Multi-fidelity modeling improves the efficiency of the design cycle by combining information from a small set of observations of the high-fidelity function and large sets of observations of the low-fidelity, fast-to-evaluate functions. In the context of Bayesian optimization, the most popular multi-fidelity model is the auto-regressive (AR) model, also known as the co-kriging surrogate. The main building block of the AR model is a weighted sum of two Gaussian processes (GPs). Therefore, the AR model is well suited to exploit information generated by sources that present strong linear correlations.
Research Report

Internal Boundaries of Metal Additive Manufacturing: Future Process Selection

2022-03-11
EPR2022006
In the early days, there were significant limitations to the build size of laser powder bed fusion (L-PBF) additive manufacturing (AM) machines. However, machine builders have addressed that drawback by introducing larger L-PBF machines with expansive build volumes. As these machines grow, their size capability approaches that of directed energy deposition (DED) machines. Concurrently, DED machines have gained additional axes of motion which enable increasingly complex part geometries—resulting in near-overlap in capabilities at the large end of the L-PBF build size. Additionally, competing technologies, such as binder jet AM and metal material extrusion, have also increased in capability, albeit with different starting points. As a result, the lines of demarcation between different processes are becoming blurred.
Technical Paper

Numerical Analysis of Lightweight Materials and their Combinations to Understand their Behaviour against High Pressure Shock Loading

2023-05-25
2023-28-1311
Materials play a key role in our day to day life and have shaped the industrial revolution to a great extent. Right selection of material for meeting a particular objective is the key to success in today’s world where the cost as well as sustainability of any equipment or a system have assumed greater significance than ever before. In automotive industry, materials have a definitive role as far as the mobility and safety is concerned. Materials that can absorb the required energy or impact can be manufactured through different manufacturing as well as metallurgical processes which involves appropriate heat treatment and bringing correct chemical compositions etc. However, they can also be formed by simpler methods such as combining certain materials together in the form of layered combinations to form light weight composites.
Technical Paper

Design and Development of Fuel Tank for High Mobility Military Vehicle

2023-05-25
2023-28-1342
Fuel tank is considered as safety component in the vehicle, and it has to be tested to meet the safety requirements as per AIS 095. Earlier, fuel tanks were manufactured by using Hot dipped cold rolled steel material and the weld zones are applied with Anti-corrosive coating. Few fuel tanks were reported with Corrosion problems. The root cause analysis was carried out considering the raw material, manufacturing process, transpiration, storage and usage. As an improvement, the new fuel tank is designed to eliminate the limitations of the existing fuel tank. 3D modeling was done to check space and mounting requirement in the layout and used for volume calculations. FE analysis was performed to check structural stability. Emphasis given on Interchange-ability to cater the new fuel tanks in place of old as spares requirement. The fuel tank has developed with Alumina steel material.
Standard

Fuze Well Mechanical Interface

2019-09-03
CURRENT
AS5680B
This interface standard applies to fuzes used in airborne weapons that use a 3-in fuze well. It defines: Physical envelope of the fuze well at the interface with the fuze. Load bearing surfaces of the fuze well. Physical envelope of the fuze and its connector. Mechanical features (e.g., clocking feature). Connector type, size, location and orientation. Retaining ring and its mechanical features (e.g., thread, tool interface). Physical envelope of the retaining ring at the interface with the fuze. Physical space available for installation tools. Torque that the installation tool shall be capable of providing. This standard does not address: Materials used or their properties. Protective finish. Physical environment of the weapon. Explosive interface or features (e.g., insensitive munitions (IM) mitigation). Charging tube. Torque on the retaining ring or loads on the load bearing surfaces.
Training / Education

Metals Bundle

Anytime
Almost 75% of all elements are metals. Metals can be classified as either ferrous or non-ferrous and generally conduct electricity and heat well. Most metals are malleable and ductile and are, in general, heavier than other elemental substances. The following six eLearning courses are included in the Materials bundle. Each course is approximately one-hour in duration. See topics/outline for additional details. Introduction to Metals, Ferrous Metals, Nonferrous Metals, Classification of Steel, Essentials of Heat Treatment of Steel Exotic Alloys
Journal Article

Numerical Analysis of Armored Fighting Vehicle Escape Hatch Subjected to Mine Blast Loading Using Coupled Eulerian-Lagrangian Technique

2023-03-30
Abstract This article describes the research work taken to compare the effect of air blast and surface-buried mine blast loading on an armored fighting vehicle (AFV) escape hatch, using the coupled Eulerian-Lagrangian (CEL) technique. Two types of escape hatch were considered for the study, namely, the flat plate version and double-side curved-plate version. To evaluate the research methodology used in this investigation, initially, a published experimental work on a circular plate subjected to air blast was chosen and a benchmark simulation was carried out using the CEL technique to establish the simulation procedure. Then the established procedure was utilized for further analysis. It was observed that the variation in the deformation between the published literature and the simulation work was well within the acceptable engineering limits.
Training / Education

High Temperature Materials Bundle

Anytime
Metals and alloys have different melting ranges depending on their chemistry. High temperature metals are much harder at room temperature, have exceptionally high melting points (usually above 2000 degree Celsius), and are resistant to wear, corrosion and deformation. The following five eLearning courses are included in the High Temperature Materials bundle.  Each course is approximately one-hour in duration. See Topics/Outline for additional details.
Standard

Diminishing Manufacturing Sources and Material Shortages (DMSMS) Management Practices

2015-07-01
CURRENT
GEB1
This document includes a standard set of management practices that can be used, or espoused, by the OEMs for use during the design and development of electronic systems to mitigate the effects of future Diminishing Manufacturing Sources and Material Shortages (DMSMS). While this document focuses primarily on microelectronic devices, the methods described here may also apply to other commodities.
Technical Paper

Warrior Injury Assessment Manikin Oblique Vertical Testing

2018-11-12
SC18-22-0008
Abstract - The Warrior Injury Assessment Manikin (WIAMan) was developed to assess injury in Live Fire Test and Evaluation (LFTE) and laboratory development tests of vehicles and vehicle technologies subjected to underbody blast (UBB) loading. While UBB events impart primarily vertical loading, the occupant location in the vehicle relative to the blast can result in some inherent non-vertical, or off-axis loading. In this study, the WIAMan Technology Demonstrator (TD) was subjected to 18 tests with a 350g, 5-ms time duration drop tower pulse using an original equipment manufacturer (OEM) energy attenuating seat in four conditions: purely vertical, 15° forward tilt, 15° rearward tilt, and 15° lateral tilt to simulate the partly off-axis loading of an UBB event. The WIAMan TD showed no signs of damage upon inspection. Time history data indicates the magnitude, curve shape, and timing of the response data were sensitive to the off-axis loading in the lower extremity, pelvis, and spine.
Training / Education

Ferrous Metals Bundle: Steel and Cast Iron

Anytime
Ferrous metals contain iron and are prized for their tensile strength and durability. Most are magnetic and contain a high carbon content which generally makes them, with the exception of wrought iron and stainless steel, vulnerable to rust. The following seven eLearning courses are included in the Ferrous Materials Bundle: Steel and Cast Iron. Each course is approximately one-hour in duration. Modules include: Introduction to Physical Properties, Introduction to Mechanical Properties, Introduction to Metals, Hardness Testing, Ferrous Metals, Classification of Steel, Essentials of Heat Treatment of Steel.
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