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The material known as 75ST is a new high strength aluminum alloy that can be used in certain aircraft structural applications to effect a saving in weight or an increase in strength or both over designs using other alloys. However, the structural engineer should be well acquainted with the advantages and limitations of this material before utilizing it in design.

This paper documents the development of the capability to test MAVs (Micro Air Vehicles) in the University of Florida’s wind tunnel facility. The main goal of this work was to obtain, with a reliable procedure, good quality experimental data from wind tunnel tests of air vehicles at low Reynolds numbers, in the order of 100,000. An overview of the instrumentation and data analysis techniques will be presented, followed by some samples of results from tests on specific aircraft. A standard aerodynamic characterization test was developed to perform a “quick” System Identification (SID) characterization of an air vehicle. The requirements for those tests were established by the modeling and control portion of the project. The test procedure was aimed to find the main aerodynamic derivatives that will be used to model the aircraft and design the flight control system. Three distinctly different vehicles ranging in size from 60 cm to 15 cm wingspan are discussed.

V/STOL wind tunnel testing performed over the past several years has been guided largely by the well established practices of conventional low speed wind tunnel testing. Since this approach has not always been satisfactory, a recent investigation was made to determine the adequacy of current V/STOL testing methods. The study was particularly relevant to tests of a four-propeller tilt-wing airplane configuration, but the knowledge gained from this study is also applicable to other types of V/STOL airplanes. The principal result of the investigation was finding that some testing practices for conventional models are not adequate for V/STOL models. The key factors that separate conventional and V/STOL testing were found to be the balance interference tares, model power, and angle-of-attack range.

This paper demonstrates the results of the analysis of the current practical situation in product reliability and durability as well as accelerated stress testing development. High stress testing is now the basic source for obtaining initial information to provide a prediction of a product's reliability and durability. This paper shows that this testing cannot offer information for the accurate prediction of reliability and durability, because the product degradation process during the testing differs from the product degradation process during the actual field situation. As a result, the time to failures also differs.

Unmanned Aerial Vehicles (UAV) are being deployed in military, law enforcement, search & rescue, scientific research, environmental & climate studies, reconnaissance and other commercial and non-commercial applications on a large scale. A design and development of landing gear system has been taken up for a UAV. This paper presents the design optimization of structural components of Wheel-Brake & Fork assembly pertaining to the Main Landing Gear (MLG) for a UAV. The wheel, fork, axle and brake unit constitute the wheel assembly. The wheel-brake assembly is assembled with the strut assembly and forms the Landing gear system. The Fork is the connecting member between the shock strut and the axle containing the wheel-brake assembly. As the fork and axle are subjected to shock loads while landing, the strength of these components are very much essential to withstand the dynamic loads.

The technological advances made in the weaving of advanced materials show true promise for the automotive, aerospace and other industries. The capability to design and fabricate a fabric matching unique specifications exist today. Engineers have the liberty of specifying fiber placement and combinations unheard of before. The understanding of weaving can provide the Engineer with creative options during the design and fabrication of composite parts. Their work is made easier with a basic understanding. The ART of weaving has been with civilization since before the pharoahs of Egypt. The weaving of advanced composite materials represents only a second of time in comparison. That fact is made evident by the lack of written material delineating processes and methods by which advanced materials are woven into end products. I will attempt to introduce, explain and demonstrate the developing science and art of weaving with advanced composite materials.

The purpose of this research is to characterize the wear resistance of wheel treads made of polymeric woven and non-woven fabrics. Experimental research is used to characterize two wear mechanisms: (1) external wear due to large sliding between the tread and rocks, and (2) external wear due to small sliding between the tread and abrasive sand. Experimental setups include an abrasion tester and a small-scale merry-go-round where the tread is attached to a deformable rolling wheel. The wear resistance is characterized using various measures including, quantitatively, by the number of cycles to failure, and qualitatively, by micro-visual inspection of the fibers’ surface. This paper describes the issues related to each experiment and discusses the results obtained with different polymeric materials, fabric densities and sizes. The predominant wear mechanism is identified and should then be used as one of the criteria for further design of the tread.

This paper provides a focus on the R & D of solid sorption coolers and heat pumps made in the Luikov Heat & Mass Transfer Institute (CIS Countries Association “Heat Pipes”) under Thermacore, Inc. Agreement. Commercial and space applications of sorbent systems offer an attractive alternative to compression systems and liquid sorption system in cooling, heating and air conditioning. The key elements of solid sorption machines are the chemical compressors-adsorbers. Two categories of solid sorption system are analyzed: adsorbents (MgA, NaX zeolites, carbon fibre “Busofit” with water, acetone, NH3), and compounds with chemical reaction and physical adsorption (CaCL2+ carbon fibre “Busofit” with NH3). These systems differ in one very important aspect: the adsorption equilibrium is bivariant, chemical reaction is monovariant. Some promising results with zeolite-water and NH3, “Busofit” with acetone and NH3 are received.

Virtual Testing by means of computer simulations of physical models contains a large potential for the improvement of the verification and certification process of an aircraft's high lift system. Rising system complexity (driven by the need for improved A/C efficiency) on one side and shortened development cycles on the other side lead to the need of an extension of the existing, classical test methods. This is why Airbus High Lift Test Department continuously works since a couple of years on the introduction of Virtual Testing as an additional, equivalent test means besides existing, established physical means of compliance such as Test Rigs (TR) and Real Time Simulators, the so called Functional Integration Benches (FIB).

Improving the verification and certification process of the high lift system by introduction of virtual testing is one of the approaches to counter the challenges related to testing of future aircraft, in terms of performing more tests of more complex systems in less time. The quality of the applied modelling methods itself and the guarantee of a completely traceable simulation lifecycle management along the aircraft development are essential. The presentation shows how existing processes for the management of all test related data have to be extended to cover the specifics of using multi body simulation models for virtual tests related to high lift failure cases. Based on a demonstrator, MSC Software GmbH and Airbus developed and are still refining the SimManager based “High Lift System Virtual Test Portal”. This portal has to fulfil on the one side global requirements like data management, data traceability and workflow management.

Integration of ground-based testing into the airborne testing process is presented in terms of an advanced test and analysis concept. Based on the discussion, that running a simulator is less expensive than performing a test flight, means of combining both methodologies are being presented and discussed. The idea is to perform selected tests on ground-based facilities under test flight conditions. This is called Virtual Flight Testing. For explanation of this idea an example is given and a representative result is presented. Another main pillar of this advanced test and analysis concept is on-line analysis. A recent tool for this purpose is on-line simulation, which is introduced with a brief overview together with an illustrative example. The paper gives an introduction into DASA’s efforts to increase efficiency of the testing process. The main goal is an early feedback of test information into the design process in order to improve this process.

In the research of lightweighting solutions, the use of CFRP has dramatically increased during the last two decades to represent today about 50 percent of the materials used in the recent commercial aircrafts. However designers are still facing the challenge to accelerate the insertion of new materials for applications. One of the main challenge concerns the reduction of the material certification time which relies only on experimental procedure. Globally speaking, there is a need for a material definition and certification in a numerical form to meet platform requirement and that allows to reduce cost and development time of new material by replacing manual tests with advanced simulation. A comprehensive simulation process is then proposed and described. This process allows to define a complete test matrix in order to generate B-basis allowable for a given material system. Several aspects have to be considered.

Wing Anti-Icing Systems (WAIS) are integral part of a wing design. Their presence ensures safety in all-weather conditions. In standard designs, the WAIS are fitted in the slat internal structure and runs throughout its span in between the ribs. Given its critical function, such a system has to pass qualification test. The test specification is dictated by international standards. In the case discussed in this article, the standard adopted is the RTCA DO-160G “Environmental Conditions and Test Procedures for Airborne Equipment”. In particular, the work presented here concerns with the Vibration environmental test. The standard prescribes a number of dynamic tests to be carried out on the AIS: random, shock and sine excitation tests have to be performed in order to study their effect on the parts composing the Anti-Icing System. The standard prescribes vibration levels at the attachment locations of the AIS to the wings' ribs.

As model-based systems engineering is proliferating throughout the aerospace industry as a method to manage the development of complex cyber-physical systems, opportunities to leverage formal methods for verification and validation purposes are significant. As a system model described in SysML can contain the level of semantics required to define strict system requirements, it is possible to create a translation tool to generate SRL (SADL (Semantic Application Design Language) Requirements Language) to leverage ASSERT™ (Analysis of Semantic Specifications and Efficient generation of requirements-based Tests) for verification and validation of the system requirements. SADL [13] is a controlled English grammar that translates directly into OWL (Web Ontology Language) [14]. As part of the validation of the SRL requirements, ASSERT™ leverages a theorem prover to look for conflict and completeness errors.

Safety related nuclear power plant systems and components are qualified for seismic adequacy by analysis, tests, or a combination of both. These seismic qualification methods are biased towards the conservative side due to the variability associated with the inherent randomness in the phenomenon being simulated and those related to the incomplete knowledge about the simulation. Major sources of variability in the test method of qualification are addressed and their approximate variations are enumerated. These variations are useful in assessing the overall conservatism and in estimating the probabilistic strength capacity of equipment.

The SAE G-27 committee was tasked by ICAO to develop a performance-based packaging standard for lithium batteries transported as cargo on aircraft. The standard details test criteria to qualify packages of lithium batteries & cells for transportation as cargo on-board passenger aircraft. Lithium batteries and cells have been prohibited from shipment as cargo on passenger aircraft since 2016. This paper summarizes the results of the tests conducted by Transport Canada and National Research Council Canada to support the development of this standard with evidence-based recommendations. It includes a description of the test specimens, the test set up, instrumentation used, and test procedures following the standard as drafted to date. The study considered several lithium-ion battery and cell chemistries that were tested under various proposed testing scenarios in the draft standard.

VGCF/Carbon composites have been shown to demonstrate high thermal conductivity, comparable to that of CVD diamond, implying utility in high performance electronic packaging. VGCF/carbon composites are unlike diamond in that, typical of most fiber reinforced composites, designed physical properties are incorporated into the composite through fiber architecture. Thermal performance for die cooling is frequently determined by the thermal impedance of the package, measured from the junction to ambient, ϕja, or jucntion to case, ϕjc. This paper reports the results of this test on VGCF/carbon composites with a 1D architecture.

Many engineering systems operating in a cold environment are challenged by ice accretion, which unfavorably affects their aerodynamics and degrades both their performance and safety. Precise characterization of ice adhesion is crucial for an effective design of ice protection system. In this paper, a fracture mechanics-based approach incorporating single cantilever beam test is used to characterize the near mode-I interfacial adhesion of a typical ice/aluminum interface with different surface roughness. In this asymmetric beam test, a thin layer of ice is formed between a fixed and elastically deformable beam subjected to the applied loading. The measurements showed a range of the interfacial adhesion energy (GIC) between 0.11 and 1.34 J/m 2, depending on the substrate surface roughness. The detailed inspection of the interfacial ice fracture surface, using fracture surface replication technique, revealed a fracture mode transition with the measured macroscopic fracture toughness.

Microbial control in spacecraft is currently achieved by environmental control of humidity, forced air filtration, and the use of antimicrobials for surface application (i.e., isopropyl alcohol) and biocidal agents for treatment of potable and technical water supplies (e.g., iodine and iodide or ionic and colloidal silver). Continuous monitoring is required to ensure water quality for shuttle and ISS missions. Water distribution systems for exploration missions on the Crew Exploration Vehicle (CEV) may benefit from a single-application surface-bound antimicrobial coating that limits microbial surface attachment. Consequently, we investigated the use of 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride, a commercially available quaternary aminosilane that bonds permanently to surfaces and inhibits microbial growth. To assess its suitability in spacecraft applications, we previously employed a test method to assess the effectiveness of aminosilane coatings on textiles.