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Toward a modeling Tool for Business Continuity Management
No full textInternational audienceNowadays, Business continuity management (BCM) has become an important topic in most sectors of activity, for government organizations as well as for business owners and their stakeholders, especially after the pandemic of COVID-19. For years, companies and organizations have been working on their BCM strategies to deal with disruptive events like floods, terrorist attacks, and pandemics. As the business environment is becoming increasingly competitive, having a well-established and clear BCM tool is a priority rather than merely providing verbose documents of business continuity plans(BCP) in which management rules and instructions are specified in a textual manner that makes their implementation very difficult. This present research sets out to fulfill this need by designing a dedicated tool, named “BeC@RE”, which supports the efficient application of the BCM framework. Therefore, a literature analysis was conducted to investigate the scientific foundations of BCM in order to point out the main components and features needed to be implemented and supported by this dedicated tool. “BeC@RE” tool was implemented using the ADOxx meta-modeling platform which is openly available, allowing its adoption and use in BCM practice
Mechanical behavior of a NextelTM 610/alumina-silica, oxide/oxide ceramic matrix composite
No full textInternational audienceOxide/oxide ceramic composites can be used for structural applications operating continuously at temperatures between 500°C and 900°C under oxidizing environment, such as in areas close to aircraft engines. In particular, composites based on a matrix combining alumina and silica are promising because this system has good mechanical properties up to 1000°C and allows to limit the grain coarsening in Nextel 610 alumina fibers. In this work, the mechanical behavior of a Nextel 610/alumina-silica oxide/oxide ceramic matrix composite is studied. The matrix system initially associates submicron particles of alumina (AKP-50, d50 = 200 nm, Sumitomo Chemical Co. Ltd.) and colloidal particles of silica (Ludox AS-40, d50 = 20 nm, Grace Davison). Unidirectional composite plates were manufactured. The fibers were impregnated with the suspension by contact molding and the green body was subsequently sintered. The composite material was then characterized. In particular, the elastic properties and the behaviors in diametral compression and in 4-point bending were determined. The mechanical behavior of the material is closely related to its microstructure which results from the flow of the viscous silica phase during sintering. In addition, the influence of the alumina-silica ratio is discussed. Relationships between processing/microstructure/properties were finally established by considering the behavior of the matrix system during the various stages of the manufacturing
Inspection d'assemblages mécaniques par une approche Deep Learning 3D : résultats préliminaires
No full textInternational audienceNos travaux de recherche sont menés dans le cadre du laboratoire de recherche commun "Inspection 4.0" entre IMT Mines Albi/ICA et la société DIOTA spécialisée dans ledéveloppement d’outils numériques pour l’industrie 4.0. Dans cet article, nous nous intéressons au contrôle de conformité d’ensembles mécaniques aéronautiques complexes (typiquement un moteur d’avion en fin ou en mi- lieu de chaine d’assemblage). Un scanner 3D porté par un bras de robot permet l’acquisition de nuages de points 3D pour la phase d’inspection. Nous avons à notre disposition un modèle CAO de l’assemblage mécanique à inspecter, et c’est ce modèle qui guidera notre démarche. Nous mettons en œuvre des techniques de classification 3D par Deep Learning. Ces modèles d’apprentissage profond sont formés sur des données synthétiques et simulées, générées à partir des modèles CAO. Plusieurs approches sont proposées et des résultats sur des acquisitions réelles sont pré-sentés
Hardware architecture for the evaluation of BCP robustness indicators through massive data collection and interpretation
No full textInternational audienceRecently, the concept of robustness measurement has become clearly important especially with the rise of risky events such as natural disasters and mortal pandemics. In this context, this paper proposes an overview of a hardware architecture for massive data collection in the aim of evaluating robustness indicators. This paper essentially addresses the theoretical and general problems that the scientific research is seeking to address in this area, offers a literature review of what already exists and, based on preliminary diagnosis of what the literature has, presents a new approach and some of the targeted findings with a focus on the leading aspects, having a primary objective of explaining the multiple aspects of this research work
Speckle pattern creation methods for two‐dimensional digital image correlation strain measurements applied to mechanical tensile tests up to 700°C
No full textInternational audienceThe purpose of this study is to develop novel speckle pattern techniques for digital image correlation (DIC) kinematic measurements of mechanical tests at high temperatures, typically from 400 to 700°C. In this context, the speckle pattern should not only meet morphological criteria (size, density, distance) in order to improve spatial resolution, but it should also present a high contrast and resist high temperature and strain levels. To find a speckle pattern matching these specifications, a comparison was performed on six types of speckle made using different techniques. First, a computer-generated speckle pattern that meets DIC criteria was numerically designed to produce six types of speckle pattern. Next, the speckle patterns produced using these six techniques were compared in terms of speckle morphology, image quality and adherence to titanium alloy TA6V material at high temperatures. From 25 to 600°C, the speckle pattern made by the technique combining anodisation and laser engraving named M5 technique gave the best contrast (highest value of mean intensity gradient [MIG] and Shannon entropy value) and the adherence of 200% of strain measurements to the TA6V material. At 700°C, speckle image quality is considerably reduced due to oxidation of the titanium alloy, and this may not be suitable for DIC measurements. Only the speckles produced by painting in which the paint plays a protective role provide with a better speckle contrast compared with other techniques. However, these speckle patterns enable only a strain measurement of 22% by the DIC method. This article concludes with guidelines for producing a speckle pattern suitable for high-temperature mechanical tests
Effect of poly(ether ether ketone) degradation on commingled fabrics consolidation
No full textInternational audienceThe effects of poly(ether ether ketone) (PEEK) degradation on consolidation of commingled preforms have been investigated. Contrary to what could be expected, under the same processing conditions, consolidation of the preforms systematically results in a high porosity content, above 10%. Fourier Transform Infrared spectrophotometry (FTIR) and Gel Permeation Chromatography (GPC) have shown small molecular structure modifications of PEEK yarns compared to the raw material. These modifications have been attributed to sizing of PEEK filament. Calorimetric (DSC) and rheological analyses have demonstrated that the presence of sizing in the preforms have huge consequences on the degradation kinetics. The crystallization temperature decreases and the viscosity increases significantly. This acceleration of the degradation kinetics is the reason of the poor consolidation behavior during composite manufacturing. The conditions of melt-spinning under which the neat PEEK is transformed into filament are therefore a key factor of PEEK degradation
Characteristics and Evolution of Nitrogen in the Heavy Components of Algae Pyrolysis Bio-Oil
No full textAn error was discovered in the original paper. The sentence “These algae were dried at 105 °C for 20 h, then pulverized and sieved to <30 μm before pyrolysis” should read as “These algae were dried at 105 °C for 20 h, then pulverized and sieved to <0.613 mm before pyrolysis”.International audienceAlgae pyrolytic bio-oil contains a large quantity of N-containing components (NCCs), which can be processed as valuable chemicals, while the harmful gases can also be released during bio-oil upgrading. However, the characteristics of NCCs in the bio-oil, especially the composition of heavy NCCs (molecular weight ≥200 Da), have not been fully studied due to the limitation of advanced analytical methods. In this study, three kinds of algae rich in lipids, proteins, and carbohydrates were rapidly pyrolyzed (10–25 °C/s) at different temperatures (300–700 °C). The bio-oil was analyzed using a Fourier transform ion cyclotron resonance mass spectrometer equipped with electrospray ionization, and the characteristics and evolution of nitrogen in heavy components were first obtained. The results indicated that the molecular weight of most heavy NCCs was distributed in the 200–400 Da range. N1–3 compounds account for over 60% in lipid and protein-rich samples, while N0 and N4 components are prominent in carbohydrate-rich samples. As temperature increases, most NCCs become more aromatic and contain less O due to the strong Maillard and deoxygenation reactions. Moreover, the heavier NCCs were promoted to form lighter compounds with more nitrogen atoms through decomposition (mainly denitrogenation and deoxygenation). Finally, some strategies to deal with the NCCs for high-quality bio-oil production were proposed
Effect of PEEK degradation on commingled fabrics consolidation
No full textInternational audienceThe effects of PEEK degradation on consolidation of commingled semi-finished products have been investigated. Two commingled semi-finished products provided by two different suppliers have been studied and compared to a powdered fabric based on the same PEEK grade. Both were manufactured from aligned AS4 carbon and PEEK yarns but the first product referred as the NCF1 has a lower commingling level than the second one identified as the NCF2. Contrary to what could be expected, under the same processing conditions, consolidation of the NCF1 and the NCF2 systematically results in a high porosity content, above 10%. Fourier Transform Infrared spectrophotometry (FTIR) in ATR mode and Gel Permeation Chromatography (GPC) have shown small molecular structure modifications of PEEK yarns compared to the raw material, such as a shift of molar mass distributions towards lower molar mass and the appearance of C-H absorption bands attributed to non-aromatic alkanes. These modifications have been attributed to sizing of PEEK filament. Calorimetric (DSC) and rheological analyses have demonstrated that the presence of sizing in the semifinished products have huge consequences on the degradation kinetics. The crystallization temperature decreases and the viscosity increases significantly. This acceleration of the degradation kinetics is the reason of the poor consolidation behavior during composite manufacturing. The conditions of melt spinning extrusion under which the neat PEEK is transformed into filament are therefore a key factor of PEEK degradation
Impact of cellulose properties on its behavior in torrefaction: commercial microcrystalline cellulose versus cotton linters and celluloses extracted from woody and agricultural biomass
No full textInternational audienceBiomass composition on cellulose, hemicelluloses and lignin determinates its behavior in torrefaction (200–350 °C, default-oxygen atmosphere). Up to now, commercial microcrystalline cellulose was typically used to represent cellulose behavior in biomass torrefaction models based on macromolecular components. The objective of this work is to evaluate the impact of cellulose properties on its behavior in torrefaction, so as to identify the most suitable cellulose sample for modelling. To do this, five extracted celluloses from woody and agricultural biomass, commercial microcrystalline cellulose (Avicel) and four cotton linters tailored to different degrees of polymerization (DP) were considered. Cellulosic samples were deeply characterized in terms of fiber analysis, molar mass distribution (MMD), hydrodynamic behavior (SEC-RALS) and allomorphic structure. Cellulosic samples were torrefied in a thermogravimetric analysis up to two temperatures, leading to partial (300 °C) and total (350 °C) cellulose degradation. Extracted celluloses and Avicel cellulose degradation profiles showed strong differences at 300 °C. Polymer MMD, dispersity and the presence of residual hemicellulose sugars, especially xylose, strongly impacted cellulose degradation through torrefaction. Extracted celluloses presented high purity, narrow MMD and high DP, but a cellulose II structure due to mercerization. This cellulosic allomorph was shown to be more reactive, but it led to an identical final solid mass loss. The observed hydrodynamic behavior and the probable preservation of cellulose amorphous areas from native cellulose may also influence polymer structural behavior in torrefaction. Finally, at least one-order-of-magnitude DP variation was shown to be required to see an impact in cellulose degradation profile through torrefaction