Bibliografie tematiche / Certification de durabilité

Letteratura scientifica selezionata sul tema "Certification de durabilité"

Autore: Grafiati

Pubblicato: 1 giugno 2024

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Articoli di riviste sul tema "Certification de durabilité":

Piketty, Marie-Gabrielle, Maria-Célia Martins De Souza e Isabel Garcia Drigo. "Certification environnementale et durabilité au Brésil". Économie rurale, n. 303-304-305 (1 giugno 2008): 169–83. http://dx.doi.org/10.4000/economierurale.674.

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DI ROBERTO, Hadrien, Carolina MILHORANCE, Ndèye SOKHNA DIENG e Elsa SANIAL. "L’agroforesterie en contexte post-forestier : perspectives et controverses d’une mise à l’agenda politique en Côte d’Ivoire". BOIS & FORETS DES TROPIQUES 356 (4 settembre 2023): 81–91. http://dx.doi.org/10.19182/bft2023.356.a37121.

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En Côte d’Ivoire, l’agroforesterie devient une notion incontournable après une déforestation massive pour les cultures de plantation. Depuis les années 2010, le terme se généralise dans le vocabulaire politique, les normes internationales de durabilité et la communication des entreprises chocolatières. Cette note examine comment l'agroforesterie s’est imposée dans l'agenda politique ivoirien. Adoptant une approche compréhensive et à partir d’une soixantaine d’entretiens et des documents politiques, elle analyse la manière dont la notion d’agroforesterie est mobilisée en Côte d’Ivoire, les instruments de sa promotion et les controverses qu’elle suscite. D’abord, ce travail montre que la mise à l’agenda de l’agroforesterie en Côte d’Ivoire se fait suivant des canaux pluriels. Différents instruments de promotion de l’agroforesterie se côtoient, tels que les normes de certification privée, la norme africaine régionale de durabilité pour le cacao, les paiements pour services environnementaux ou encore un dispositif national dit « Agro-Forêt », issu du nouveau Code forestier. Ensuite, malgré le consensus sur la promotion de l'agroforesterie, sa définition large permet à des acteurs aux intérêts divergents de s'approprier le concept. Ce travail met par ailleurs en évidence la pluralité des objectifs et des perspectives que recouvre la notion en Côte d’Ivoire. Il identifie ainsi des controverses concernant les critères du système agroforestier, sa finalité, la place des agriculteurs, l’échelle d’analyse et la temporalité à considérer. En définitive, cette note contribue à expliciter les traductions politiques plurielles d’une notion issue des sciences. Les liens complexes entre les recherches biophysiques et la pratique politique soulignent l'importance de prendre en compte cette interface pour une meilleure conception de l'agroforesterie et une transition efficace.

Ruf, François. "Les standards dits durables appauvrissent-ils les planteurs de cacao ? Interactions entre déforestation en Côte d’Ivoire et au Libéria, crédit à l’achat d’engrais et baisse des cours". Cahiers Agricultures 30 (2021): 38. http://dx.doi.org/10.1051/cagri/2021024.

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Pendant des siècles, combinés avec le travail de migrants, la forêt et la rente forêt ont été les principaux facteurs de production du cacao. C’est le modèle universel du cacao, qui a fait de la Côte d’Ivoire le premier producteur mondial. Mais le niveau de déforestation est tel qu’une partie des planteurs doivent trouver des alternatives à la rente forêt, notamment l’engrais minéral. Cet intrant chimique est de fait un facteur d’amélioration des rendements et a priori des revenus. Cependant, si la consommation d’engrais chimique est poussée par le « système », composé des Transnational Corporations (TNC) du cacao, des coopératives, des agences de crédit, des organisations non gouvernementales internationales et des labels de cacao dit « durables », n’y a-t-il pas danger d’effets inverses : contribution à l’excès d’offre de cacao, baisse du cours mondial, endettement et appauvrissement des planteurs ? À partir de trois enquêtes auprès de 150 à 250 planteurs entre 2013 et 2017, d’une enquête auprès de 41 coopératives en 2017 et d’un suivi des prix du cacao et de l’engrais sur 30 ans, l’étude aborde le rôle du prix relatif cacao/engrais et du crédit sur la consommation d’engrais, et leur impact sur la chute du cours du cacao en 2016–2017. L’impact est certain, même si le processus d’expansion cacaoyère par le binôme migration-déforestation reste le facteur essentiel de la hausse de l’offre et de la chute du cours. Le discours selon lequel les gains de rendement vont créer un « cacao durable » et dissuader les planteurs de défricher les forêts reste un mythe. Les migrations continuent aux dépens des toutes dernières forêts classées du pays, à l’est vers Abengourou, à l’ouest vers Blolequin, Man et Touba. Là encore, en dépit de leur communication sur la durabilité, les certifications ont totalement échoué : le cacao de Côte d’Ivoire dépend encore beaucoup de la déforestation. Enfin, de l’autre côté du fleuve Cavally, la grande forêt dense du Libéria disparaît à son tour, sur la voie d’un nouveau boom du cacao. Même si les responsabilités sont partagées avec les politiques publiques, que reste-t-il de « durable » dans la certification et les actions de la majorité des TNC ? Le fossé entre leur communication virtuelle et la réalité n’a jamais été aussi grand.

VEISSIER, I., R. BOTREAU e P. PERNY. "Évaluation multicritère appliquée au bien-être des animaux en ferme ou à l’abattoir : difficultés et solutions du projet Welfare Quality®". INRAE Productions Animales 23, n. 3 (14 settembre 2010): 269–84. http://dx.doi.org/10.20870/productions-animales.2010.23.3.3308.

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Face au développement en Europe de programmes de certification d’élevages mettant en avant le respect du bien-être animal, le projet Welfare Quality® a proposé à l’Union Européenne d’établir un modèle d’évaluation globale des exploitations (fermes ou abattoirs) au regard du bien-être des animaux. Ce modèle repose sur une évaluation multicritère dans laquelle 12 critères de bien-être, regroupés en 4 principes, ont été définis. Après avoir identifié les mesures nécessaires pour vérifier qu’une exploitation est conforme aux différents critères, le modèle a été progressivement construit. Il aboutit à un classement des exploitations en quatre catégories reflétant le niveau de bien-être (d’excellent à très faible). Pour ce faire, des méthodes multicritères ont été utilisées, évitant ainsi les écueils d’une agrégation naïve de l’information (comme les sommes pondérées qui autorisent les pleines compensations entre critères, ce qui n’est pas compatible avec le concept de bien-être). Différentes personnes (chercheurs en sciences animales ou sociales, porteurs d’enjeux) ont été consultées au moyen de jeux de données virtuelles sur lesquelles elles devaient donner une appréciation. Le modèle a été développé et paramétré afin de refléter ces appréciations. Une analyse a posteriori des résultats produits montre que le modèle accorde la priorité aux animaux en moins bon état tout en tenant compte de l’état moyen du troupeau, et qu’il limite fortement les compensations entre critères. Cet exemple montre qu’en suivant cette méthodologie rigoureuse, il est possible d’aider l’évaluation d’un concept multidimensionnel, même si cet exercice comporte des choix de valeurs qu’il convient d’expliciter et de modéliser. La méthodologie suivie pour construire ce modèle d’évaluation du bien-être peut être transposée pour évaluer d’autres concepts multidimensionnels comme la durabilité des systèmes de production.

Molent, L., e R. Singh. "Using the lead crack framework to reduce durability test duration". Aeronautical Journal 124, n. 1276 (24 settembre 2019): 814–20. http://dx.doi.org/10.1017/aer.2019.73.

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ABSTRACTAircraft full-scale fatigue tests are expensive and time-consuming to conduct but are a critical item on the certification path of any aircraft design or modification. This paper outlines a proposal that trades cycling hours for increased detail in the teardown of a metallic test article. A method for determining the equivalent demonstrated crack size (and crack growth curve) at the mandated test life utilising the lead crack framework is demonstrated. It is considered that the test duration can be significantly reduced, whilst still achieving all the desired outcomes of a certification program.

Jones, Rhys, Daren Peng, John G. Michopoulos e Anthony J. Kinloch. "Requirements and Variability Affecting the Durability of Bonded Joints". Materials 13, n. 6 (23 marzo 2020): 1468. http://dx.doi.org/10.3390/ma13061468.

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This paper firstly reveals that when assessing if a bonded joint meets the certification requirements inherent in MIL-STD-1530D and the US Joint Services Standard JSSG2006 it is necessary to ensure that: (a) There is no yielding at all in the adhesive layer at 115% of design limit load (DLL), and (b) that the joint must be able to withstand design ultimate load (DUL). Secondly, it is revealed that fatigue crack growth in both nano-reinforced epoxies, and structural adhesives can be captured using the Hartman–Schijve crack growth equation, and that the scatter in crack growth in adhesives can be modelled by allowing for variability in the fatigue threshold. Thirdly, a methodology was established for estimating a valid upper-bound curve, for cohesive failure in the adhesive, which encompasses all the experimental data and provides a conservative fatigue crack growth curve. Finally, it is shown that this upper-bound curve can be used to (a) compare and characterise structural adhesives, (b) determine/assess a “no growth” design (if required), (c) assess if a disbond in an in-service aircraft will grow and (d) to design and life in-service adhesively-bonded joints in accordance with the slow-growth approach contained in the United States Air Force (USAF) certification standard MIL-STD-1530D.

Chowdhury, Nabil, Wing Kong Chiu e John Wang. "A Review of Damage Tolerant Design, Certification and Repair in Metals Compared to Composite Materials". Advanced Materials Research 891-892 (marzo 2014): 1597–602. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1597.

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A review of some of the various fatigue models introduced over the years for both metallic materials, in particular aluminium alloys followed by fatigue and durability concerns associated with composite materials. The move towards light weight and high stiffness structures that have good fatigue durability and corrosion resistance has led to the rapid move from metal structures to composite structures. With this brings the added concern of certifying new components as the damage mechanisms and failure modes in metals differ significantly than composite materials such as carbon fiber reinforced polymers (CFRP). The certification philosophy for composites must meet the same structural integrity, safety and durability requirements as that of metals. Hence this is where the challenge now lies. Substantial work has been conducted in the reparability of composite structures through bonding using various adherend thicknesses and joint types and has been shown to have higher durability than mechanically fastened repairs for thin adherends however these are currently unacceptable repair methods as they cannot be certified. Repairs are designed on the basis that the repair efficiency can be predicted and should be designed conservatively with respect to the various failure modes and include the surrounding structure.

Abdi, F., Y. Xue, M. Garg, B. Farahmand, J. Housner e K. Nikbin. "An analysis approach toward FAA certification for damage tolerance of aircraft components". Aeronautical Journal 118, n. 1200 (febbraio 2014): 181–96. http://dx.doi.org/10.1017/s0001924000009064.

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Abstract This paper presents a novel analysis approach by considering multiple crack interaction in achieving FAA certification for durability and damage tolerance of exterior attachment installations on an aircraft fuselage according to FAA policy on Certification by Analysis-Supported-by-Test (CAST). Durability and damage tolerance evaluation of an aircraft component requires assessment of damage initiation and fatigue crack propagations under service loading, which consists of complex loading types, paths and variable amplitudes. Both simulation and service experience showed that multiple cracks developed in the fuselage skin and doublers that are made of wrought aluminum alloys. Progressive failure analysis (PFA) tool was used to simulate the fatigue damage initiation life using a scale-down stress-life property. A virtual crack closure technique (VCCT) was implemented to evaluate fatigue crack growth with interactions between cracks from different parts in a component, which preserves conservativeness. The fatigue crack growth data is obtained uniquely from an analytical extension of fatigue crack growth data of thin aluminum sheet. Fatigue crack growth analysis showed that only a few initiated cracks propagated steadily before a crack became visible under inspection, which was validated by comparison to service history. Eventually one crack became dominate in the fracturing process thereby setting an inspection time. Analysis also showed that fatigue damage state in the components at the designed operational life will not exceed the static safety requirements. Therefore, FAA accepted the damage tolerance analysis and the aircraft retained certification with no need for repair.

Peng, Daren, Rhys Jones, Andrew S. M. Ang, Victor Champagne, Aaron Birt e Alex Michelson. "A Numerical Study into the Effect of Machining on the Interaction between Surface Roughness and Surface Breaking Defects on the Durability of WAAM Ti-6Al-4V Parts". Metals 12, n. 7 (29 giugno 2022): 1121. http://dx.doi.org/10.3390/met12071121.

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The airworthiness certification of military aircraft requires a durability analysis be performed using linear elastic fracture mechanics (LEFM). Furthermore, such analyses need to use a valid small crack growth equation. This paper focuses on the effect of rough surfaces and the effect of machining the surface on the durability of AM parts using LEFM and a valid small crack growth equation for the material. To this end, this paper analyses the effect of surface roughness on wire and arc additively manufactured (WAAM) Ti-6Al-4V titanium parts and the effect of machining on the durability of a part. The analysis reveals that the life of the component is a relatively strong function of the degree of surface roughness, and that the durability of a specimen is a strong function of the local radius of the curvature of the trough. It also appears that surfaces with tall narrow roughness will not overly benefit from partial machining of the surface.

Peng, Daren, Victor K. Champagne, Andrew S. M. Ang, Aaron Birt, Alex Michelson, Sam Pinches e Rhys Jones. "Computing the Durability of WAAM 18Ni-250 Maraging Steel Specimens with Surface Breaking Porosity". Crystals 13, n. 3 (3 marzo 2023): 443. http://dx.doi.org/10.3390/cryst13030443.

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The durability assessment of additively manufactured parts needs to account for both surface-breaking material discontinuities and surface-breaking porosity and how these material discontinuities interact with parts that have been left in the as-built state. Furthermore, to be consistent with the airworthiness standards associated with the certification of metallic parts on military aircraft the durability analysis must be able to predict crack growth, as distinct from using a crack growth analysis in which parameters are adjusted so as to match measured data. To partially address this, the authors recently showed how the durability of wire arc additively manufactured (WAAM) 18Ni-250 maraging steel specimens, where failure was due to the interaction of small surface-breaking cracks with surface roughness, could be predicted using the Hartman–Schijve variant of the NASGRO crack growth equation. This paper illustrates how the same equation, with the same material parameters, can be used to predict the durability of a specimen where failure is due to surface-breaking porosity.

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Tesi sul tema "Certification de durabilité":

Ollendorf, Franziska. "The transformative potential of corporate social responsibility in the global cocoa-chocolate chain : Insights from sustainability certification practices in Ghana". Electronic Thesis or Diss., Toulouse 2, 2020. http://www.theses.fr/2020TOU20078.

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Cette étude examine les implications de la responsabilité sociale des entreprises (RSE) des entreprises transnationales (ETN) appliquée à leurs chaînes de valeur. Prenant le cas d'un projet de certification de la durabilité du cacao UTZ au Ghana, l'étude analyse le processus de mise en œuvre d’un projet de la RSE et ses résultats localement. La chaîne mondiale du cacao et du chocolat (GCCC) est un cas particulièrement intéressant pour cette étude car elle est confrontée à des défis complexes en matière de durabilité, notamment l'extrême pauvreté des planteurs de cacao et la dégradation de l'environnement dans les zones de production. Par conséquent, des multiples projets de RSE se sont généralisés au cours des dernières décennies. L'étude interroge comment les stratégies de RSE affectent les conditions de durabilité et qui en bénéficie finalement. Ainsi, elle met l'accent sur les changements dans l'organisation du secteur cacao au niveau local au Ghana et sur les perspectives futures des planteurs de cacao. L'étude révèle que la RSE aide plutôt les ETN à accroître leur influence sur la production locale de cacao au lieu de surmonter les principaux défis de durabilité dans la GCCC
This study engages with the implications of a Corporate Social Responsibility (CSR) of Transnational Corporations (TNCs) in their supply chains. Taking the case of an UTZ cocoa sustainability certification project in Ghana, the study examines the implementation process of a transnational CSR intervention and its local outcomes. The Global Cocoa-Chocolate Chain (GCCC) is a particular interesting case for this study because the GCCC is facing complex sustainability challenges, most notably the extreme poverty of millions of cocoa farmers and environmental degradation in production areas, and therefore, CSR projects became widespread over the past decades. The study explores how CSR strategies affect sustainability conditions in a supply chain and who is finally benefitting from it. Thereby, it puts a particular emphasis on changes in the organization of the local level Ghana’s cocoa sector linked to CSR and in farmers perspectives. The study reveals that CSR rather helps TNCs to increase their influence over local cocoa production instead of overcoming key sustainability challenges in the GCCC

Gamboa-H, Jhonny D. "Analyse comparative de l’approche bioclimatique et de la méthode LEED en architecture". Thèse, 2016. http://hdl.handle.net/1866/16073.

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Motivé par l’évolution de la production architecturale durable dans les pays d’Amérique latine, et plus particulièrement en Colombie, mon projet de recherche porte sur l’adaptation de l’architecture à ce nouveau contexte. L’approche architecturale traditionnelle à la prise en compte de l’énergie et du climat est l’architecture bioclimatique : reproduite à partir de connaissances et techniques ancestrales remontant à la conception de l’abri, cette dernière étudie les phénomènes physiques associés au confort thermique afin de les reproduire dans une nouvelle architecture. De nouvelles méthodes d’évaluation environnementale se sont développées dans les dernières décennies pour améliorer l’intégration environnementale des bâtiments. Ces méthodes privilégient la normalisation des solutions et utilisent des systèmes de certification pour reconnaître la performance environnementale et énergétique des bâtiments. Le résultat visé est la conformité aux standards internationaux de durabilité. Ce mémoire porte sur l’analyse comparative de l’architecture bioclimatique et de la certification environnementale à partir de la structure des sujets abordés par LEED, une des méthodes les plus connues d’une telle certification. Cette comparaison permet de constater que les deux approches sont motivées par les mêmes préoccupations environnementales mais que leurs méthodes d’intégration de ces préoccupations diffèrent, en particulier quant à la prise en compte des facteurs locaux et globaux.
Motivated by the development of sustainable architectural production in the countries of Latin America, particularly in Colombia, my research focuses on the adaptation of architecture to this new context. The traditional approach to the integration of energy and climate is bioclimatic architecture. This way is based on the reproduction of knowledge through the use of ancestral techniques that were acquired over time, and which evolved from shelter design. The bioclimatic architecture studies the physical phenomena in relation to thermal comfort to reproduce in a new architectural style. New environmental assessment methods have been developed in recent decades to improve environmental integration in buildings. These methods give priority to standardization of solutions and use certification systems to recognize the environmental and energy performance of buildings. The expected results are in compliance with international sustainability standards. This thesis focuses on the comparative analysis of bioclimatic architecture and environmental certification using the structure and the topics addressed by LEED, one of the best-known methods of such certification. This comparison shows that the two approaches are motivated by the same environmental concerns but their methods of integration of these concerns differ, particularly with regard to the consideration of local and global factors.

Libri sul tema "Certification de durabilité":

Shimokawa, Toshiyuki. Probabilistic approach to the certification for fatigue durability of composite structures. Tokyo: National Aerospace Laboratory, 1989.

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Capitoli di libri sul tema "Certification de durabilité":

Echtermeyer, Andreas T. "Integrating Durability in Marine Composite Certification". In Solid Mechanics and Its Applications, 179–94. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7417-9_9.

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"Certification privée de la durabilité des activités de pêche". In Études de l'OCDE sur la politique commerciale, 287–302. OECD, 2006. http://dx.doi.org/10.1787/9789264013766-23-fr.

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Shattuck, Annie, e Magali Urbain. "La certification de la durabilité est-elle efficace ? Analyse de la « Table ronde sur les biocarburants durables »". In Agrocarburants : impacts au Sud ?, 161–78. Éditions Syllepse, 2011. http://dx.doi.org/10.3917/syll.cetri.2011.01.0162.

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Abdi, Frank, Harsh Baid e Amirhossein Eftekharian. "Advanced composite wind turbine blade design and certification based on durability and damage tolerance". In Durability of Composite Systems, 203–70. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-818260-4.00005-3.

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Lattauer, Philip. "Recherches sur la Sustainability". In Recherches sur la Sustainability, 104–20. EMS Editions, 2023. http://dx.doi.org/10.3917/ems.cheva.2023.01.0104.

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Dans ce chapitre, nous souhaitons examiner la durabilité dans le contexte du concept de responsabilité sociale des entreprises (RSE) en prenant l’exemple d’une moyenne entreprise multinationale (PME). Dans le monde d’aujourd’hui, la RSE et la question de la durabilité jouent un rôle de plus en plus important. Mais comment la mise en œuvre se déroule-t-elle dans le contexte particulier des petites et moyennes entreprises (PME) multinationales ? Dans ce contexte, des sujets et des questions génériques auxquels les entreprises de toutes tailles sont confrontées entrent en ligne de compte : quelles certifications ou quels labels sont envisagés ou attendus par les parties prenantes ? Quel est l’élément déclencheur de la mise en œuvre de la RSE dans un projet ? Quels moyens spécifiques les PME ont-elles trouvés pour canaliser ou simplifier les enjeux ? En prenant l’exemple d’une entreprise, nous montrons comment des informations peuvent être obtenues pour soutenir le développement et la mise en œuvre d’une stratégie de RSE ou de durabilité et, dans un deuxième temps, nous illustrons comment les sous-domaines de l’entreprise peuvent être priorisés dans la mise en œuvre.

Atti di convegni sul tema "Certification de durabilité":

Deo, R. B. "Durability and Damage Tolerance Certification of Composite Structures". In ASME 1996 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/imece1996-0619.

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Abstract Several recent applications of polymer matrix, graphite fiber composites to operational aircraft structures have illustrated a need for well defined approaches or methodologies to demonstrate compliance with airworthiness certification requirements. This paper presents a review of the currently used compliance criteria, substantiating data required, and the methodologies available to address durability and damage tolerance certification of aircraft composite primary structures.

"CARES Sustainable Constructional Steel Certification Scheme". In SP-326: Durability and Sustainability of Concrete Structures (DSCS-2018). American Concrete Institute, 2018. http://dx.doi.org/10.14359/51711055.

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Ball, Dale, D. Norwood e Stephanie TerMaath. "Joint Strike Fighter Airframe Durability and Damage Tolerance Certification". In 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference
14th AIAA/ASME/AHS Adaptive Structures Conference
7th. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2006. http://dx.doi.org/10.2514/6.2006-1867.

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Endo, H., M. Hartnagel, A. Buschbeck e M. Schonfeld. "Spin Testing Improves Electrified Propulsion Rotor Design for Production and Certification". In 2023 AeroTech. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-1021.

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<div class="section abstract"><div class="htmlview paragraph">There is a demonstrated need for effective design verification testing to support certification strategies for nascent electric motors and electric propulsion systems. Design efforts pursue efficiency pushing electrified propulsion rotors to be lighter and incorporate greater power density; however, there is no clear path established for supporting structural integrity and durability test requirements as required by global certification agencies.</div><div class="htmlview paragraph">Application of new materials, unique rotor design characteristics, and modified certification requirements drive unusual requirements for rotor modeling substantiated by component test data that addresses complex stress distribution characteristics.</div><div class="htmlview paragraph">Our paper addresses testing electrified propulsion rotors using spin test protocols adapted to support integrity and durability test goals. We further incorporate key concerns for planning and executing component spin tests of rotating structures necessary to support global engine certification efforts. Results from component tests are effective for mitigating risks associated with the preservation of certification test schedules and potential end product safety issues.</div><div class="htmlview paragraph">This paper presents data measurement techniques that are incorporated with specific spin tests to enhance the value of acquired data. Adapted test protocols include Overspeed and Low cycle fatigue (LCF) tests, which are more relevant types of spin tests for certification purposes.</div><div class="htmlview paragraph">Innovative measurement techniques for capturing the rotor growth behavior for both mappings the speed-dependent growth trends and the circumferential profile of deforming rotor under centrifugal load generate useful data to evaluate materials and structural behavior affecting performance up to failure.</div></div>

Hansen, E., ø. Nielsen, E. Møller e R. Peuhkuri. "How to Determine when a New Building Product is Suitable - Certifications and Experience". In XV International Conference on Durability of Building Materials and Components. CIMNE, 2020. http://dx.doi.org/10.23967/dbmc.2020.074.

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ROACH, DENNIS, TREVOR LYNCH-STAUNTON, BRIAN SHAIGEC e DERRICK FORMOSA. "ASSESSING THE PERFORMANCE CVM SENSORS FOR MONITORING THE 737 AFT PRESSURE BULKHEAD". In Structural Health Monitoring 2023. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/shm2023/36819.

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Current maintenance operations and integrity checks on aircraft require personnel entry into normally-inaccessible or hazardous areas to perform necessary nondestructive inspections. To gain access for these inspections, structure must be removed, sealant must be removed and disassembly processes must be completed. The use of in-situ sensors, coupled with remote interrogation, can be employed to overcome a myriad of inspection impediments stemming from accessibility limitations, complex geometries, the location and depth of hidden damage, and the isolated location of the structure. Reliable Structural Health Monitoring (SHM) systems can automatically process data, assess structural condition, and signal the need for specific maintenance actions. This paper presents an OEM-airline-SHM vendor-regulator effort to realize these benefits by moving Comparative Vacuum Monitoring (CVM) technology into routine use in airline maintenance programs. A certification program has been completed to validate CVM sensors for surface crack detection on the 737 Aft Pressure Bulkhead (APB). Formal and comprehensive CVM technology validation and certification was guided by a recently-released FAA Issue Paper which addresses the full spectrum of issues including design, deployment, durability and performance. For accurate SHM validation to occur, all relevant environments - which may include separate fatigue and environmental response components - were properly simulated in the tests. Flight tests also played an important role in assessing overall CVM system performance under normal aircraft operations. Validation tests were designed to address the CVM equipment, the health monitoring task, the resolution required, the sensor interrogation procedures, the conditions under which the monitoring will occur, and the potential inspector population. The test results will be presented in light of the overall CVM certification plan. Such SHM deployment programs are allowing the aviation industry to confidently make informed decisions about the proper utilization of SHM. These programs also streamline the regulatory actions and certification measures needed to ensure the safe application of SHM solutions.

Tryon, Robert G., Animesh Dey, Richard A. Holmes e Ganapathi Krishnan. "Computational Models to Predict the Structural Reliability of Aerospace Systems". In ASME 2013 Conference on Frontiers in Medical Devices: Applications of Computer Modeling and Simulation. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fmd2013-16090.

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Three case studies are presented in which computational-based methodologies have been used to assess structural reliability in the aerospace industry. The studies involve hot section turbine disks of a helicopter engine, fan blades of a commercial airline engine and bearings in an auxiliary power unit. In all cases, the results of the computational models were used to support the certification process for design and application changes. The statistical variation in design and usage parameters including geometry, materials, speed, temperature and other environmental factors are considered. The response surface approach was used to construct a durability performance function. This performance function is used with the first order reliability method (FORM) to determine the probability of failure and the sensitivity of the failure to the design and usage parameters. A hybrid combination of perturbation analysis and Monte Carlo simulation is used to incorporate time dependent random variables. System reliability is used to determine the system probability of failure, and the sensitivity of the system durability to the design and usage parameters.

Bhatt, Ankur, John Gandolfo, Kunal Vedpathak, Chen Jiang, Eric Jordan, Benjamin Lawler e Brian Gainey. "Experimental Study of Low Thermal Inertia Thermal Barrier Coating in a Spark Ignited Multicylinder Production Engine". In Energy & Propulsion Conference & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-1617.

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<div class="section abstract"><div class="htmlview paragraph">Thermal barrier coatings (TBCs) have long been studied as a potential pathway to achieve higher thermal efficiency in spark ignition engines. Researchers have studied coatings with different thicknesses and thermophysical properties to counteract the volumetric efficiency penalty associated with TBCs in spark ignition. To achieve an efficiency benefit with minimal charge heating during the intake stroke, low thermal inertia coatings characterized by their larger temperature swings are required. To study the impact of low thermal inertia coatings in spark ignition, coatings were applied to the cylinder head, piston crown, intake and exhaust valve faces, and intake and exhaust valve backsides. Tier III EEE E10 certification gasoline was used to keep the experiments relevant to the present on-road vehicles. This study is aimed at analyzing durability of the coatings as well as efficiency and emissions improvements. Thus, a 100-hr. durability test was conducted to assess the durability of the coatings. Pseudo-cold start testing was also compared between the coatings and metal baseline to investigate any benefits pertaining to emissions reduction during cold starts. These experimental results show that low thermal inertia coatings can be developed for spark ignition engines that survive a 100-hr. durability test, though there is no significant change in steady state engine performance with the application of these coatings. However, there was a substantial reduction in particulate matter and unburned hydrocarbon emissions during pseudo-cold start testing.</div></div>

Glista, Stefan M., Weibe Postema, Lily Arcusa e Brad Clark. "F-22 MECSIP Lessons Learned: Risk Based Fatigue Scatter Factors High Durability Margin Analysis Using Miner’s Rule and Weibull Analysis". In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63753.

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A top-level safety requirement for aircraft is that the probability of structural failure, resulting in the loss of aircraft, shall be less than 1 × 10−7 per flight hour. A reasonable approach to justify fatigue scatter factors is to derive them from this top-level safety requirement. The minimum scatter factor that can be justified using Weibull analysis is a function of the material data and stress level. Typical results at realistic stress levels range from 8 to 16 lifetime analytical margin to the characteristic life of the S-N data set. Weibull analysis results demonstrate that a 4-life time test provides high probability of detecting a design margin shortfall. Scatter Factors are also derived for design loads and life tracking loads. The analysis discussion addresses single-point-failure safety critical structure; however, a Weibull based probability analysis for multiple-load-path structure with dependent failure mechanisms is also included. Graphical and statistical proofs justify the material scatter factors. The F-22 program uses Weibull based probability analysis for design margins, testing, certification and life management. We call the risk based scatter factor approach High Durability Margin Analysis (HDMA).

Desmond, Michael, e Darris White. "Predictions of Structural Testing Characteristics for Wind Turbine Blades". In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-12288.

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Static and fatigue structural testing of wind turbine blades provides manufacturers with quantitative details in order to improve designs and meet certification requirements. Static testing entails applying extreme load cases through a combination of winches and weights to determine the ultimate strength of the blade while fatigue testing entails applying the operating design loads through forced hydraulics or resonant excitation systems over the life cycle of the blade to determine durability. Recently, considerable efforts have been put forth to characterize the reactions of wind turbine blades during structural testing in order to develop load and deflection predictions for the next generation of blade test facilities. Incorporating years of testing experience with historical test data from several wind turbine blades, curve fits were developed to extrapolate properties for blades up to one hundred meters in length. Furthermore, conservative assumptions were employed to account for blade variations due to inconsistent manufacturing processes. In short, this paper will outline the predictions of wind turbine blade loads and deflections during static and fatigue structural testing.

Rapporti di organizzazioni sul tema "Certification de durabilité":

Lin, Shin-Hui, e Chao-Lung Chen. Feasibility of Using Half Useful Life Mileage Accumulation for Motorcycle Certification Durability Tests in Taiwan. Warrendale, PA: SAE International, ottobre 2013. http://dx.doi.org/10.4271/2013-32-9055.

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