Search

This paper focuses on an innovative end-of-use strategy: repurposing, defined as a manufacturing process through which products nearing their end-of-life are reused in different applications. We re...

International audience; Circular economy is an effective strategy to reduce globally the environmental impacts of our consumption society. However, the introduction of circular economy scenarios implies major changes in our consumption mode and in our industrial systems. Because of changes in the value chain, the new circular consumption and production scenarios imply new needs, new requirements and then characteristics for the production and organization of these circular offers. The aim of this paper is to present a characterization of the repurposing and upgrading strategies, in order to facilitate design activities related to new circular industrial scenarios. This paper presents the research approach used to characterise the upgrading and repurposing strategies and then the characteristics that have been established investigating academic and industrial projects using literature review and interviews.

In the assessment and planning of energy systems, use of simulations is a crucial step. They allow the quantification of techno-economic potential to subsequently aid decision-making amongst various technological or design choices. In these software, environmental analysis is either too simplified or neglected completely since a conventional life cycle assessment (LCA) study might not be feasible to account for different variabilities related to scale, scope, energy carriers, etc. In this paper, we integrate techno-economic analysis of hydrogen production from polymer exchange membrane (PEM) electrolysis with life cycle assessment. This step-by-step guideline will be useful especially for professionals working in energy system design to develop a LCA model for PEM in their respective software. Consequently, this will enable them to take environmental indicators into account while planning facilities.

The advent of renewable energy systems has led to an increase in decentralised energy systems. Consequently, the last 10 years have seen development of specialised software such as HOMER, iHOGA, EnergyPro, RETScreen and TRNSYS to analyse these systems. This study compares these software in detail especially in terms of the environmental assessment. It is concluded that these software do not adequately include environmental analysis since only 1 out of 5 software considers more than one life cycle stage, neglecting other upstream/downstream emissions. Furthermore, the emphasis is on emissions such as NOx and SO2 that are usually associated with fossil fuel utilization. As the energy systems are becoming increasingly complex, especially with storage technologies such as hydrogen and batteries, emissions ‘shift’ away from the operating stage. Moreover, it becomes essential to look further than global warming potential and take into account other impacts such as depletion of critical materials, acidification, eco-toxicity, etc. Hence, it becomes essential to take into account entire life cycle stages and provide comprehensive environmental impacts along with the already available techno-economic capabilities to the designers and decision-makers. Finally, this study provides recommendations on the methodology to include environmental analysis in the investigated software.

International audience; Recently, the combination of additive and subtractive manufacturing technologies is gaining significant attention from both the industrial and academic sectors. Due to consolidated advantages of individual techniques, this combination provides the capability of producing innovative products, and opens new perspectives for developing new remanufacturing/manufacturing strategies. In this paper, an innovative strategy is proposed. The strategy aims to manufacture a new part directly from an EoL part (or existing part), using a sequence of additive and subtractive manufacturing processes. The existing part is transformed into the new part without involving the material recycling phase. This paper particularly focuses on the environmental assessment of the proposed strategy. For this purpose, a methodology based on the life cycle assessment method is developed. The environmental trade-offs between the proposed strategy and the conventional strategy are also discussed through the case study. The conventional strategy uses conventional processes (such as material recycling, casting and machining) to manufacture the new part, whereas the proposed strategy is based on combining electron beam melting (EBM) and CNC machining processes. The results show that the proposed strategy becomes more environmentally friendly when the material volume of existing part reused increases more than 60%. The proposed methodology can help designers and manufacturers to select the most suitable strategy to manufacture new parts from existing parts with minimum environmental impacts.

The development of additive manufacturing (AM) technology provides the possibility of producing complex parts (including internal complex features) that are difficult to manufacture by machining. However, AM technologies also have some limitations, such as low-dimensional accuracy and long production times. Recently, combining additive manufacturing technology with CNC machining is gaining significant attention. This combination not only takes advantages of individual techniques, but also minimizes their disadvantages. In this paper, taking into account consolidated benefits of such technique combination, an alternative remanufacturing strategy is proposed. The strategy allows end-of-life parts (or existing parts) to be reused directly for manufacture of new parts (or final parts) without involving the material recycling stage. In addition, the final part is intended for another product, namely the existing part has a new life and new usage in its life cycle. To achieve the geometry and quality of final part, a sequence of additive, subtractive manufacturing and inspection operations will be generated. For this purpose, additive manufacturing features and machining features are first identified and extracted from the available information of the existing and final parts. This paper particularly focuses on a feature extraction approach, which is developed using the knowledge of additive manufacturing and CNC machining processes, technological requirements, and available resources. The major criteria and constraints have been defined and applied during the feature extraction process. The extracted features and their relationships will be used as the inputs for designing the process planning. Finally, a case study is used to illustrate the proposed approach.

International audience; This study is focused on the development of environmentally friendly recycling method for selective recovery in a closed loop manner of Co and Pt from Pt3Co/C catalyst used as the PEMFC cathode. Pt and Co selective separation was carried out using two different hydrometallurgical alternatives based either on ion exchange resin or solvent extraction. The recycling process was optimized in order to maximize the platinum recovery yield, which reached 83% and 77% of the Pt initially present in the MEA using respectively solvent extraction or ion exchange resin separation alternatives. The recovered platinum alkaline solutions have been further used for Pt/C particles synthesis via a modified polyol method and it was shown that although the resin alternative resulted in slightly lower recovery yield, the catalyst prepared via this alternative satisfied morphological and electrochemical properties for the oxygen reduction reaction (ORR) by performing similarly to a commercial state-of-art Pt/C catalyst. The feasibility of closed loop Pt/C catalyst recycling was thus proven. The environmental impacts of the two recycling alternatives have been compared using life cycle assessment methodology (LCA) and similar impacts have been found for both alternatives from the point of view of the entire MEA life cycle. The ion exchange resin alternative has thus been selected as the most appropriate one.

National audience; Ce travail vise à développer une méthodologie permettant de contribuer à fermer la boucle de l'économie circulaire en reconfigurant des pièces mécaniques à l'aide d'outils de fabrication additive et soustractive. La reconfiguration des pièces se définit ici comme un processus par lequel des pièces en fin de vie sont modifiées pour rendre possible leur retour dans un état neuf prolongeant leur durée de vie, ces pièces sont ici utilisées dans une application similaire à leur utilisation première. Cette stratégie s'appuie sur les possibilités offertes par le remanufacturing et son utilisation comme un outil pour participer à la soutenabilité des systèmes de production.

PurposeLife cycle analysis (LCA) is more and more used in the context of electromagnetic product design. But it is often used to check a design solution regarding environmental impacts after technical and economical choices. This paper aims to investigate life cycle impact optimization (LCIO) and compare it with the classical life cycle cost optimization (LCCO). Design/methodology/approachFirst, a model of a dry-type transformer using different materials for windings and the magnetic core is presented. LCCO, which is a mixed continuous-discrete, multi-objective technico-economic optimization, is done using both deterministic and genetic algorithms. LCCO results and optimization performances are analyzed, and an LCA is presented for a set of optimal solutions. The final part is dedicated to LCIO, where the paper shows that these optimal solutions are close to those obtained with LCCO. FindingsThis paper investigated LCIO using an environmental impacts model that has been introduced in the optimization framework Component Architecture for the Design of Engineering Systems. The paper shows how a mixed continuous-discrete, multi-objective technico-economic optimization can be done using an efficient deterministic optimization algorithm such as Sequential Quadratic Programming. Thanks to the technico-economic-environmental model and the efficient optimization algorithm, both LCCO and LCIO were performed separately and together. It has been shown that optimal solutions are similar, leading to the conclusion that only one modeling is required (economic or environmental) but on the life cycle. Originality/valueThe classical sequential methodology of design is improved here by the use of a model of calculation of the environmental impacts allowing the optimization. This original optimization allowed the authors to show that an analysis of the life cycle from an economic point of view or from an environmental point of view led to quasi-equivalent technical solutions. The key is to take into account the life cycle of the product.

In recent years, additive manufacturing (AM) techniques provide the capability to build parts directly from CAD models by adding materials layer by layer. This technique allows producing complex parts that are not able to be manufactured by machining. However, AM techniques also present some limitations, such as poor surface quality, reduced dimensional accuracy, limited materials available and long production time when compared to CNC machining. To overcome these limitations, the combination of additive and subtractive (i.e. CNC machining) technologies is today considered as a promising solution for current manufacturing issues. This paper demonstrates the feasibility of combining these technologies for the manufacture of given parts from end-of-life (EoL) parts (or existing parts). The proposed approach aims to reuse existing parts directly to produce new parts (or final parts), avoiding the material recycling stage. The final parts are then intended for another product, namely the existing parts have a new life in their life cycle. This paper particularly focuses on the design of process planning for combined additive and subtractive processes, using the concept of AM and machining features. The design of process planning is performed based on the knowledge of additive and subtractive processes, the technological requirements, and the available resources. To respect constraints and considerations in manufacturing processes, different rules are defined and applied in the design of process planning. Finally, the efficacy of the proposed approach is demonstrated through the case study.

National audience; Les batteries contribuent de manière forte aux impacts environnementaux globaux du système véhicule électrique. Sur le plan environnemental, leur gestion en fin de vie apparait comme un élément important de la chaine globale. La réduction des impacts environnementaux peut passer par la prolongation de la du-rée de vie de ces batteries en les réutilisant dans d'autres applications : on parle ici de repurposing. Il est dès lors nécessaire de penser, dès les phases amont de conception, l'ensemble du cycle de vie et notamment chacun des deux usages successifs ainsi que les phases de re-fabrication intermédiaires. Pour définir les paramètres de conception qui viennent en appui à des batteries repurposées, des experts batteries ont été interrogés. Pour ce faire, une grille d'entretien a été développée. Le but visé est l'identification des paramètres clefs en conception, que ce soit en termes de produits, de processus de fabrication ou de modèle d'affaires envisagé. Les premiers résultats font remonter des problématiques liées aux aspects de sécurité des batteries , aux profils des sollicitations et de densité d'énergie.

This paper presents a direct material reuse approach. The approach consists in producing new parts directly from existing components avoiding the material recycling stage, using a combination of additive and subtractive technologies. The proposed approach seems able to reduce resources consumption and waste during the manufacturing process. The major steps of the approach are presented. The process planning for combined additive and subtractive processes is particularly discussed. The process planning is designed through the feature concept, based on the knowledge of individual processes, technological requirements, and available resources. Finally, the feasibility of proposed approach is validated through a case study.

International audience; A proton exchange membrane (PEM) fuel cell, an alternative to combustion processes that consume fossil resources, is used to convert energy stored in the form of hydrogen into electricity. The membrane-electrode assembly (MEA), the core of this system, contains platinum, a noble metal, which is a limited resource. This paper presents an environmental assessment of a recycling process for the platinum catalyst contained in the MEA of a PEM fuel cell. During this study, four hydrometallurgical platinum recovery processes from Pt/C particles have been developed at the laboratory scale. The considered process alternatives are composed of the four following steps: leaching, separation, precipitation and filtration. Approximately 76% of the platinum can be recovered as [NH4]2PtCl6 salt using the most efficient process alternatives. In this case, platinum leaching is carried out with a mixture of H2O2 and HCl, followed by liquid/liquid platinum extraction and a precipitation step.The environmental assessment was performed using the SimaPro 8 tool coupled with the EcoInvent 3.1 database. The environmental impacts were estimated for a 25 cm2 active area MEA considering the production and end-of-life stages of the MEA life-cycle using the CML-IA baseline V3.02 method. The results show that more than half of the main impacts of the MEA life-cycle can be avoided for four relevant impact categories if platinum is recovered in the end-of-life of the product.

International audience; The emergence of additive manufacturing (AM) techniques in the last 30 years allows to build complex part by adding material in a layer-based fashion or spraying the material directly into the part or a substrate. Taking into account performance of these techniques in a ‘new remanufacturing strategy’ can open new ways to transform an end-of-life (EoL) part into a new part intended for another product. The strategy might allow a considerable material proportion of existing parts to be reused directly for producing new parts without passing through the recycling stage. In this work, the strategy enables the transformation of existing parts into desired parts is first presented. The strategy uses an adequate sequence of additive and subtractive operations, as well as inspection operations to achieve the geometry and quality of final parts. This sequence will be designed from a set of AM features and machining features, which are extracted from available technical information and the CAD models of existing part, and final part. The core of the paper focuses on the feature extraction approach. The approach development is based on the knowledge of AM processes and machining process, as well as the specifications of final part.

International audience; End-of-Life (EoL) strategies, and especially products' lifespan extension, are becoming key issues for more and more manufacturers. Their implementations have to be done from the design stage and may be facilitated with design methodologies and guidelines. However, if a function of the system is no longer efficient enough during its use phase, in such a way that remanufacturing and upgrading may not be considered, the system has reached its final EoL, even if it might have been used for other applications. To address such kind of situations, the present paper investigates the concept of Design-2-Life (D2L) systems. To do so, EoL strategies will be explored to understand the key issues. Then a clear explanation of D2L concept will be proposed as well as its main characteristics. Finally we will discuss the challenges of this new approach and the advantages to develop it under a PSS framework. The case of batteries used in electric cars will be used to illustrate the concept.

National audience

International audience; This paper presents the development of an efficient hydrometallurgical recovery process of platinum from Pt catalyst of PEMFC electrodes at laboratory scale, whereby leaching, Pt separation, precipitation and filtration steps were combined in order to optimize the recovery process. The efficiencies of two different leaching agents (H2O2/HCl and HNO3/HCl) and two different separation methods (liquid–liquid extraction and ion exchange resins) were compared in this study. Finally the platinum was recovered by precipitation as ammonium hexachloroplatinate (NH4)2PtCl6 (a PEMFC catalyst precursor) at the outlet of each process alternative. Thus four different process alternatives were tested and compared.At first the experiments were performed with Pt/C particles and hexachloroplatinic acid in order to study the influence of several experimental parameters on platinum recovery efficiency. Then the real PEMFC catalyst coated membranes (CCMs) were treated according to the optimized leaching/recovery process. Finally, the most efficient process alternative gave a 76% Pt recovery yield from CCMs.

International audience; Electron beam melting (EBM) has been recognized as an emerging additive manufacturing technology, which allows the production of fully dense parts from various metals. The technique builds parts using an electron beam to melt metal powder, layer by layer, in a powder bed. Thus, complex parts, including internal structures, can be made directly from 3D CAD models without special fixtures and cutting tools. Much research is conducted to study the microstructure and mechanical properties of EBM-built parts or to investigate the effects of EBM process parameters on the quality of parts. However, using EBM for building new features on an existing part has received little attention from the research community. Due to its performance, EBM seems able to transform an end-of-life (EoL) part/existing part into a new part without returning to the level of raw material. The aim of this study is to validate such principle. In this paper, an EBM machine was used to produce new Ti-6Al-4V features on a Ti-6Al-4V plate, which was considered as a useful core retrieved from an EoL product. The built samples, including EBM-built features and Ti-6Al-4V plate, were investigated in terms of their microstructure and mechanical properties. The results showed that EBM technique allows new features with a suitable microstructure and controlled mechanical properties to be built on an existing part. Moreover, the EBM-built features have a strong bond with the existing part leading to the same mechanical characteristics as original part. These demonstrate that the EBM technology has a promising potential for producing new parts from EoL parts/existing parts.

International audience; Many researches have been done to facilitate remanufacturing process and optimize its benefits, and, as a result, several tools and methodologies have been developed. This research aims to integrate these methodologies and tools into a more practical and useful integrated design framework.Since existing tools and methodologies have a wide range of applications and objectives, their interconnection is not a trivial task. The contribution of this paper is to provide an analysis grid for analyzing and classifying these existing tools (or methods) into a two-dimensional framework. The first dimension contains the four pillars of sustainable development “extended” framework (economic, social, environmental and technical aspects) identified by Fatimah [Fatimah 2013]. The second dimension is based on the six elements of a remanufacturing system (product design, reverse supply chain, information flow, employee knowledge and skill, remanufacturing operation and product marketing) proposed by Barquet [Barquet 2013]. The grid is presented and the input and output parameters of 7 existing tools (or methods) are analyzed using our grid. As a conclusion, this analysis indicates that none of the tool (or method) has a significant overlap and some interesting synergies are identified.

National audience; Les enjeux d'une production plus durable n'étant plus à démontrer, les entreprises se doivent d'intégrer la dimension environnementale dans leur processus de conception. En effet les concepteurs ont un poids important dans le développement de "produits verts" par leurs choix de conception. Ils peuvent, grâce à des outils comme l'Analyse du Cycle de Vie (ACV) évaluer l'impact environnemental d'un produit ou d'un service existant afin de les aider dans leurs prises de décisions conceptuelles. Dans cet article nous nous focaliserons sur l'étude des représentations des résultats d'ACV dans les moments critiques d'interaction entre les experts environnementaux et les autres acteurs de la conception. Pour cela nous identifierons les moments critiques d'interaction dans un processus de conception actuel, et étudierons les représentations et l'interprétation des résultats d'ACV qui leur sont associés.; Les enjeux d'une production plus durable n'étant plus à démontrer, les entreprises se doivent d'intégrer la dimension environnementale dans leur processus de conception. En effet les concepteurs ont un poids important dans le développement de "produits verts" par leurs choix de conception. Ils peuvent, grâce à des outils comme l'Analyse du Cycle de Vie (ACV) évaluer l'impact environnemental d'un produit ou d'un service existant afin de les aider dans leurs prises de décisions conceptuelles. Dans cet article nous nous focaliserons sur l'étude des représentations des résultats d'ACV dans les moments critiques d'interaction entre les experts environnementaux et les autres acteurs de la conception. Pour cela nous identifierons les moments critiques d'interaction dans un processus de conception actuel, et étudierons les représentations et l'interprétation des résultats d'ACV qui leur sont associés. Mots-clés: éco-conception, analyse de cycle de vie, représentation.

The increase in lithium batteries' (LIBs) demand implies a growing consumption of raw materials. Taking into account this rapid growth, it is necessary, from now on, to think about “life cycle” and sustainability in order to preserve and to sustain our natural resources. Based on a literature review, this chapter presents at first the life cycle assessment methodology applied to LIBs. Especially the key points of the analyzed studies will be emphasized here and some improvements will be proposed. The end-of-life stage is analyzed then and a short summary of existing recycling methods is given. Finally, it will be emphasized that the environmental impact assessment of future LIBs should be done by integrating the entire battery life cycle from resources extraction up to recycling.

The concept of sustainability was developed in order to improve the present human living standards while maintaining the availability of the natural resources for future generations. According to this definition, technological development is a way to improve the sustainability, because it enables to meet human needs by transforming natural resources into useful products. By 2050, the urban world population is expected to approximately double to an estimated 6.4 billion2 and we are aware that the Earth’s natural resources are already limited. In this context, less impacting and more efficient industrial processes’ design represents a real challenge for engineers. From now on, the impacts of new technologies have to be assessed in detail, all along their life cycle, even before their massive industrial deployment.We should be sure that the generated impacts are actually counterbalanced by the improvement of the living standards on Earth. In this chapter, we will consider new technologies related to the development and treatment of lithium batteries. In the first part, we will demonstrate how existing studiesare already taking into account environmental impacts assessment and we will particularly emphasize the main assumptions realized using life cycle assessment (LCA) approaches. In the second part, we will focus on the end-of-life (EOL) of lithium batteries to demonstrate that the entire value chain has to be considered while arbitrating on the acceptability or not of a design decision from an environmental perspective., Les batteries de type lithium connaissent et vont connaitre un essor considérable compte tenu d'une part de leurs bonnes performances et d'autre part d'une demande sans cesse croissante d'énergie notamment pour les applications transports. Cet accroissement entraîne une consommation accrue de matières premières et exige, dès aujourd'hui, de penser « cycle de vie » et « développement durable » afin de préserver et de pérenniser les ressources naturelles. Ce chapitre décrit dans un premier temps la méthodologie de l'« analyse du cycle de vie » appliquée aux batteries au lithium à partir de l'analyse de travaux publiés dans la littérature. En particulier les points clefs de ces études sont soulignés et des améliorations indispensables dans l'application de la méthode sont proposées. Dans un deuxième temps, le chapitre décrit un rapide état de l'art du recyclage et pointe la nécessité d'intégrer et de modéliser tout le cycle de vie des batteries depuis l'extraction des ressource primaires jusqu'à la fin de vie.

International audience; 'Closed loop' end-of-life strategies such as remanufacturing must be applied to create eco-efficient products. Remanufacturing may be a key element in reducing the environmental impact of products but this remains to be proved. The aim of this study is to help designers evaluate the environmental impacts of their remanufacturing process during the design phase. The first task is to identify, list and classify the various remanufacturing processes (disassembly, cleaning, sorting and controlling, reconditioning, reassembly) by type of process and then estimate the environmental impact for each process. These processes are then formalized by characterization and organised in a database. Using a simulator, the different processes can be aggregated to assess the environmental impacts of a remanufacturing line. An example is presented in the last part of this paper to illustrate the proposal.

In the last decade, in order to increase the customer satisfaction, companies faced with challenges like scarce resources and costs during the production process. Reverse logistic approach helps companies to cope with those difficulties by using different operations. Remanufacturing of used products enables companies to decrease production costs and also reduce raw material costs. This common problem is materialized in a famous heavy truck producer who wants to enter European market with a new product which is a diesel particulate filter. This study aims to design and develop a Reverse Logistic Network System that contains remanufacturing processes for the heavy truck manufacturer. The objective is to determine optimal geographical locations of remanufacturing centers considering economical and environmental impact as a cost function in the mathematical model based on Capacitated Facility Location Problem approach. (C) 2013 The Authors. Published by Elsevier B.V. Open access under CC BY-NC-ND license.

This thesis introduces the concept of geometrical behavior of mechanical assembly. The geometrical behavior is constituted by a set of algebraic relations that translate the assemblability or mobility conditions of a product. It is expressed thanks to a specific geometrical model for the early phases of product design. Firstly, this work shows the interest of the geometrical behavior to tackle multi-physics problems at the early stages of product design. This part is illustrated on a ten bar pyramid subjected to mechanical and thermal strains. Secondly, this thesis proposes a coordinate free geometrical model dedicated to the representation of mobile mechanisms. This part also indicates a technique to express the mobility conditions of a loop as mathematical equations. An application of these model and technique is proposed to express the geometrical behavior of the Bennett mechanism. Finally, this work exposes a solution to associate and compare two objects described in the above-mentioned coordinate free model. This technique is useful to compare two states of the same object used under different operating conditions. It can also be used to associate ideal and real objects to tackle tolerancing issues.; Cette thèse introduit le concept de comportement géométrique d'un assemblage mécanique. Cette notion permet de rendre compte du caractère assemblable ou mobile d'un mécanisme sous la forme d'un système de relations algébriques entre les paramètres géométriques permettant de le décrire. Dans un premier temps, cette thèse montre l'intérêt de ce concept pour traiter des problèmes faisant intervenir plusieurs effets physiques et plusieurs scénarios d'utilisation. Ce chapitre est appliqué à l'étude de l'assemblabilité d'un treillis pyramidal de conception à 4 barres décrit par un modèle géométrique non cartésien issu de la littérature. Dans un second temps, après avoir constaté le manque de modèles adaptés permettant de représenter des mécanismes mobiles, ce travail en propose un non cartésien. Il détaille aussi une méthode de mise en équation afin de traduire la mobilité d'un mécanisme. Une application de ce modèle et de la méthode est également faite. Elle permet de résoudre localement le problème de la mobilité d'un mécanisme de Bennett. Enfin, la dernière partie de ce travail expose une solution pour associer et comparer deux objets décrits par des représentations non cartésiennes. Cette technique est utile pour comparer deux états physiques du même objet utilisé dans différents scénarios pour assurer le suivi d'une exigence géométrique. Elle peut également être utilisée pour associer des objets réels et des objets idéalisés pour traiter des problèmes de tolérancement

This thesis introduces the concept of geometrical behavior of mechanical assembly. The geometrical behavior is constituted by a set of algebraic relations that translate the assemblability or mobility conditions of a product. It is expressed thanks to a specific geometrical model for the early phases of product design. Firstly, this work shows the interest of the geometrical behavior to tackle multi-physics problems at the early stages of product design. This part is illustrated on a ten bar pyramid subjected to mechanical and thermal strains. Secondly, this thesis proposes a coordinate free geometrical model dedicated to the representation of mobile mechanisms. This part also indicates a technique to express the mobility conditions of a loop as mathematical equations. An application of these model and technique is proposed to express the geometrical behavior of the Bennett mechanism. Finally, this work exposes a solution to associate and compare two objects described in the above-mentioned coordinate free model. This technique is useful to compare two states of the same object used under different operating conditions. It can also be used to associate ideal and real objects to tackle tolerancing issues.; Cette thèse introduit le concept de comportement géométrique d'un assemblage mécanique. Cette notion permet de rendre compte du caractère assemblable ou mobile d'un mécanisme sous la forme d'un système de relations algébriques entre les paramètres géométriques permettant de le décrire. Dans un premier temps, cette thèse montre l'intérêt de ce concept pour traiter des problèmes faisant intervenir plusieurs effets physiques et plusieurs scénarios d'utilisation. Ce chapitre est appliqué à l'étude de l'assemblabilité d'un treillis pyramidal de conception à 4 barres décrit par un modèle géométrique non cartésien issu de la littérature. Dans un second temps, après avoir constaté le manque de modèles adaptés permettant de représenter des mécanismes mobiles, ce travail en propose un non cartésien. Il détaille aussi une méthode de mise en équation afin de traduire la mobilité d'un mécanisme. Une application de ce modèle et de la méthode est également faite. Elle permet de résoudre localement le problème de la mobilité d'un mécanisme de Bennett. Enfin, la dernière partie de ce travail expose une solution pour associer et comparer deux objets décrits par des représentations non cartésiennes. Cette technique est utile pour comparer deux états physiques du même objet utilisé dans différents scénarios pour assurer le suivi d'une exigence géométrique. Elle peut également être utilisée pour associer des objets réels et des objets idéalisés pour traiter des problèmes de tolérancement

International audience; This paper proposes to investigate the use of a coordinate free approach for the mapping of geometrical requirement along a product life cycle. The geometry of the studied assembly is represented using a Gram matrix that is issued from a parametric model constituted of points and vectors. This parametric model is instanced for all relevant phase of the product life cycle. The calculation of instanced parameters is based on part deformation due to changing operating conditions. This calculation is carried out thanks to existing theoretical techniques. The application presented in this paper is constituted of a simple 3D case composed of 3 articulated bars disposed as a tetrahedron and subjected to some thermal expansion.

International audience; This paper presents a framework for the calculation of functional requirements at several stages of the product life cycle. It uses the TTRS/MGRE concept for the determination of dimension chains. The geometry of the assembly is represented using a parametric model constituted of points and vectors. Finally, it also integrates the calculation of part deformation due to changing operating conditions thanks to existing techniques such as finite elements.

The great majority of engineered products are subject to thermo-mechanical loads which vary with the product environment during the various phases of its life-cycle (machining, assembly, intended service use...). Those load variations may result in different values of the parts nominal dimensions, which in turn generate corresponding variation of the effective clearance (functional requirement) in the assembly. Usually, and according to the contractual drawings, the parts are measured after the machining stage, whereas the interesting measurement values are the ones taken in service for they allow the prediction of clearance value under operating conditions. Unfortunately, measurement in operating conditions may not be practical to obtain. Hence, the main purpose of this research is to create, through computations and simulations, links between the values of the loads, dimensions and functional requirements during the successive phases of the life cycle of some given product. [...]

International audience; For many years the market leadership was driven by offering better price on more product functions and services. The world is currently shifting towards social responsibility thinking. This changes the market behaviour, and leads to more innovations, such as designing new product/service/system using re-usable parts, new electric motor concepts, or inventing new chemical production procedures generating less waste, and many more opportunities. This paper introduces a research valorisation activity that aims at developing a program of training and coaching to prepare students and industry partners to this emerging innovation wave. The most outstanding particularity of this program is that it combines management and engineering aspects of sustainability in a form that empowers trainees to deploy sustainable approaches in practice. The particular target group of design engineers get equipped with fundamentally important sustainability knowledge enabling them to include sustainability considerations in their products and systems design. Eco-design is positioned as a key lever towards achieving sustainable product-service systems.

Colloque avec actes et comité de lecture. Internationale.; International audience; Nowadays, additive manufacturing technique is considered as a technique of the third industrial revolution. The technique makes it possible to build a ?real-material? part by adding materials, layer by layer, based on a CAD model. Taking into account the performances of these techniques, a new remanufacturing strategy seems possible to transform an End-of-Life (EoL) part into a new part without returning to the level of raw material. The purposes of this paper is to explore the technological feasibility of such additive manufacturing techniques for remanufacturing, and then propose the ways in order to establish a new strategy for giving a new life to EoL parts. The new parts produced are intended to be different - and have different functionalities - from the original.; La technique de fabrication additive est aujourd'hui considérée comme une technique de la troisième révolution industrielle. Cette technique permet de créer une pièce « vraie matière » par ajout de matière couche par couche à partir d'un modèle CAO. La prise en compte des performances de ces techniques dans une nouvelle stratégie de remanufacturing devrait permettre de transformer une pièce en fin de vie en une nouvelle pièce sans retourner au niveau du matériau premier. L'objectif de cet article est de découvrir la faisabilité technologique de ces techniques pour le remanufacturing, et de poser les pistes pour mettre en place une nouvelle stratégie permettant de donner une nouvelle vie aux pièces en fin de vie. Ces pièces étant destinées à un autre produit.

In recent years, combining additive and subtractive manufacturing technologies has attracted much attention from both industrial and academic sectors. Due to consolidated benefits of individual techniques, this combination provides new possibilities to manufacture products, and develop new strategies for recovering products at their end-of-life stage. This paper aims to develop a direct material reuse strategy based on such technique combination. The principle of the strategy is to manufacture new parts (or final parts) directly from end-of-life parts (or existing parts) without involving the material recycling phase. In this paper, a systematic methodology is proposed to develop the strategy. Firstly, the good mechanical characteristics of parts obtained by the strategy are confirmed. Thereafter, the design of process planning for combining additive and subtractive manufacturing processes is focused. This allows achieving the geometry and quality of final part from the existing part. The methodology for process planning design is developed in two major steps using the manufacturing feature concept, the knowledge of manufacturing processes, technological requirements, and available resources. In the first step, manufacturing features (i.e. machining and additive manufacturing features) are extracted from the information of the existing and final parts. In the second step, the process planning is generated from extracted features by respecting the relationships of features and the manufacturing precedence constraints. Finally, a case study is used to illustrate the proposed methodology.

National audience; Il existe maintenant plusieurs travaux de recherche traitant de tables input-output en flux physiques. Ces travaux sont cruciaux pour essayer de répondre aux questions sur les possibles trajectoires de nos sociétés et modes de consommations. Dans cette communication, nous souhaitons faire le pont entre ces travaux et l'analyse de flux de matières et développer une méthodologie capable de fournir des tables en flux physiques dans un formalisme commun à partir de données avec plusieurs unités physiques.

National audience; Today, the main methodology used to analyze the environmental impacts of a given system is the Life Cycle Assessment (LCA). This multi-step and multi-criteria methodology is now established in the consensus as reliable in a prospective objective. In this context, huge databases have been set up. This is the case of Ecoinvent, a particularly complete Swiss LCA database. There is currently a challenge to associate these databases, and this methodology, with other prospective models, such as the MATER model proposed by a research team from the ISTerre laboratory. The purpose of the internship described in this document is to develop a program to group production chains present in Ecoinvent, so that these groupings correspond to the structure of the MATER model, in order to extract LCA data and reuse them in this new framework. The core of the report focuses on two elements: the development of a reliable clustering algorithm, and the testing system put in place to ensure this reliability.; Aujourd’hui, la principale méthodologie utilisée pour analyser les impacts environnementaux d’un système donné est l’Analyse de Cycle de Vie (ACV). Cette méthodologie multi-étapes et multi-critères est maintenant installée dans le consensus comme fiable dans un objectif de prospective. Dans ce cadre, d’immenses bases de données ont été mises en place. C’est le cas notamment d’Écoinvent, une base de données d’ACV suisse particulièrement complète. Il y a actuellement un enjeu d’association de ces bases de données, et de cette méthodologie, avec d’autres modèles prospectifs, comme par exemple le modèle MATER proposé par une équipe de recherche du laboratoire ISTerre. L’objet du stage décrit dans ce document est de développer un programme permettant de grouper des chaînes de production présentes dans Écoinvent, afin que ces groupement correspondent à la structure du modèle MATER, dans l’objectif d’en extraire des données d’ACV et les réutiliser dans ce nouveau cadre. Le coeur du rapport se concentre sur deux éléments : le développement d’un algorithme fiable de groupement des données, et le système de test mis en place pour assurer cette fiabilité.

Un système socio-technique est un réseau liant des acteurs avec des liens de type économiques,matériels, culturels ou encore sociaux. Le changement climatique nous invitant à une grandemodification de notre société, l'imagination de nouveaux systèmes, appelées alternatives, socio-techniquesest une problématique particulièrement actuelle. L'équipe STEEP, dans laquelle j'aiexéctué mon stage, s'intéresse à l'étude des alternatives socio-techniques (AST) et notammentde leur valeur selon plusieurs critères. J'ai pu travailler sur l'un d'eux, la vulnérabilité d'une ASTqui désigne la propension de cette dernière à subir des dommages. Afin d'étudier cet aspect,la représentation et modélisation des systèmes est une étape importante sur laquelle j'ai pulargement me consacrer.Mon travail a été constitué de deux parties toutes deux portant sur la modélisation des AST,une première partie qualitative et une deuxième partie quantitative. J'ai premièrement exéctuéune revue des notions de l'approche systémique comme celle du métabolisme social ou de lavulnérabilité. J'ai ensuite pu adapté certains outils rencontrés dans l'ingénierie système pourla représentation de la vulnérabilité des AST. Ce travail a permis de réfléchir à des questionsmodélisation, de savoir ce qui peut facilement ^etre représenté et ce qui l'est un peu moins. Dansun second temps, j'ai également pu m'intéresser au problème de la réconciliation des données,domaine à la jonction entre les mathématiques appliquées et l'approche systémique, connexes àdes branches des mathématiques très intéréssantes comme la géométrie riemannienne, branchesavec lesquels j'ai du me familiariser afin de comprendre les outils utilisés. J'ai xéctué unesynthèse d'articles que j'ai pu lire où je détaille le formalisme mathématique des méthodesprésentés par ces articles.

National audience

National audience; Suite aux diverses réglementations mises en place à l’échelle européenne et nationale, la Métropole de Grenoble est en train de mettre à la disposition des habitants une possibilité de trie à la source des biodéchets. Le compostage de proximité et la collecte sélective sont en cours de déploiement sur le territoire et la démarche devrait englober toute la population d’ici 2021. Afin de valoriser énergétiquement et organiquement les biodéchets, un plan de modernisation de l’usine de compostage de Murianette en usine de méthanisation a été établi. Cet exutoire local est essentiel à la gestion territoriale de la matière organique et nécessite d’être dimensionner sur une source de déchets stable en terme de quantité, mais également en terme de durée. Ce besoin justifie la nécessité d’étudier les flux de déchets alimentaires du territoire dans le but de quantifier la production de ces ressources et de caractériser les flux de matières. De plus, une meilleure compréhension de la filière des biodéchets du territoire permettra de cerner les opportunités de réduction des quantités produites par le biais de la prévention et de la valorisation des déchets organiques. Ce sont les objectifs visés par le CODEC, un contrat d’objectifs déchets qui se veut de favoriser l’économie circulaire et le réemploi des ressources. C’est dans ce contexte que la Métropole a fait appel à l’équipe STEEP de l’INRIA afin d’apporter un état de lieux de cette filière et de comprendre les obstacles potentiels à la collecte de la matière organique. Cette étude vient compléter l’étude de INDDIGO réalisé pour le compte de la Métropole, ainsi que l’évaluation du potentiel méthanogène de AURA-EE à travers l’outil TerriSTORY. Dans la continuité de ces travaux, une méthodologie a été mise en place afin d’estimer les quantités de déchets fermentes cibles produites. Des enquêtes terrains et des recherches bibliographiques ont permis d’établir une matrice de mobilisation reflétant les caractéristiques du territoire et les objectifs poursuivis dans le Schéma Directeur des Déchets. Une cartographie des flux est ensuite présentée afin de rendre compte des destinations actuelles des gisements et de la part effectivement mobilisable pour la méthanisation dans une prospective de moyen terme.