Defining tools to address over-constrained geometric problems

International audienceThis paper proposes a new tool for decision support to address geometric over-constrained problems in Computer Aided Design (CAD). It concerns the declarative modeling of geometrical problems. The core of the coordinate free solver used to solve the Geometric Constraint Satisfaction Problem (GCSP) was developed previously by the authors. This research proposes a methodology based on Michelucci's witness method to determine whether the structure of the problem is over-constrained. In this case, the authors propose a tool for assisting the designer in solving the over-constrained problem by ensuring the consistency of the specifications. An application of the methodology and tool is presented in an academic example

Ecodesign of Li-ion batteries

International audiencePrésentation des avancements de mon travail de thèse au sein du laboratoire G-SCOP, fait à l'occasion du congrès LCM2015 à Bordeuax

A remanufacturing process library for environmental impact simulations

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

Remanufacturing de pièce par procédé additif et soustractif : Proposition méthodologique et cas d'études sur des potences de vélo

National audienceCe 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

Chapter 8. Lifecycle and sustainability

International audienceThe 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

Using additive and subtractive manufacturing technologies in a new remanufacturing strategy to produce new parts from End-of-Life parts

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.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

An Innovative Approach to Teaching Sustainable Design and Management

International audienceFor 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

Building new entities from existing titanium part by electron beam melting: microstructures and mechanical properties

International audienceElectron 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

Modular approach to material flow analysis

National audienceIn this paper, we refer to a socio-technical system as a model for the organisation of production and consumption in a given territory. This work is part of the STEEP team's "Socio-technical alternatives" research axis, which aims to provide tools and methodologies that allow stakeholders in a territory (public authorities, associations, companies, citizens) to deliberate in order to imagine and evaluate together long-term alternatives (two or three decades) for their territory. These alternative socio-technical systems should meet the needs of the populations while being compatible with various local and global constraints and limits (environmental, social). Our work focuses more specifically on a step-by-step tool for designing coherent alternatives

Vers des tables en flux physiques de l'économie française

National audienceIl 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