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Recueil de communications école d'hiver 2025 GDR ARCHI-META - DN METACMED
No full textNational audienceThe last 20 years have seen a remarkable growth in scientific interest in(elastic and mechanical) metamaterials. One of the reasons for this is thegreat potential that this subject area has in itself as a “link between differentdisciplines”, particularly acoustics and solid mechanics. In addition, through abetter mastery of architecture, it makes it possible to create complex enginee-ring systems with unconventional dynamic and quasi-static behavior.However, the literature seems to show that since its introduction in the early2000s, two almost independent macro-communities have formed around thissubject: that of acousticians, more focused on phenomenology, and that ofmechanics, more focused on methodology.However, it is clear that 1) these two communities are dealing with thesame scientific problem, and that 2) certain differences in purpose and lan-guage have given, and still give, the impression that these are two looselycoupled fields of research. This has made intercommunity dialogue insufficientuntil now. However, it is easy to see that the subjects investigated and the me-thodologies used are generally complementary. The time has come for a newcommunity to emerge, particularly at the international level.In this context, the ARCHI-META GdR proposes to seize this spontaneousconvergence and act as a catalyst to go beyond the specificities related toacoustics and mechanics, and thus to bring together a new community aroundarchitectured metamaterials. The overall objective is to get the communities(mechanics and acousticians) to work together to identify and resolve thecommon scientific issues that have come to light in recent years and to sharethe theoretical tools specific to the two communities in order to establish acommon language. This synergy will make it possible to address more effec-tively the scientific issues limiting the development of these promising techno-logies
Weighted tensorized fractional Brownian textures
No full textThis paper presents a new model of textures, obtained as realizations of a new class of fractional Brownian fields. These fields, called weighted tensorized fractional Brownian fields, are obtained by a relaxation of the tensor-product structure that appears in the definition of fractional Brownian sheets. Statistical properties such as self-similarity, stationarity of rectangular increments and regularity properties are obtained. An operator scaling extension is defined and we provide simulations of the fields using their spectral representation
Instrumentation and experimental hygrothermal investigations of a raw compressed earth brick house in Sense-City equipment: From material to building scale
No full textInternational audienc
Inverse identification of anisotropic plasticity model parameters using FEMU and a heterogeneous test
No full textInternational audienceAbstract. Accurate characterization of the anisotropic plastic behavior of sheet metals is critical for predicting their performance in forming operations. Traditional testing methods often struggle to capture complex material responses under varied loading conditions. This study focuses on combining a heterogeneous mechanical test with the Finite Element Model Updating (FEMU) technique to inversely identify the parameters from an anisotropic plasticity model. The experiments employed a specimen geometry designed through topology optimization – TopOpt, from which full-field data was extracted using Digital Image Correlation (DIC) from both surfaces. Numerical simulation was conducted using a finite element model reproducing the experimental boundary conditions, with material parameters calibrated through quasi-homogeneous tests assuming isotropic behavior. The FEMU procedure was then applied to calibrate the Swift-Voce hardening law and the Yld2004-18p yield criterion, using experimental data from both surfaces of the TopOpt specimen. This work allowed for the evaluation of the TopOpt specimen's capability to provide sufficient data for parameter identification with the results highlighting the complexity of calibrating such an advanced material model with a single experiment
Quantum-enhanced Deep Learning for Severe Weather Prediction : a 10-qubit QCNN-LSTM for Bow Echo Forecasting
No full textArticle soumis à la revue Quantum Machine Intelligence (Springer), actuellement en cours d’évaluation.We present a quantum-enhanced deep learning framework for short-term forecasting of extreme convective weather systems, specifically targeting the formation of bow echo structures through cloud prediction. Our approach integrates a Quantum Convolutional Neural Network (QCNN) with a classical CNN-LSTM pipeline, incorporating a 10-qubit variational quantum circuit executed on the lightning.qubit simulator. The model is trained using heterogeneous meteorological data (satellite images, CAPE fields, lightning activity) from the extreme storm that hit the Corsican coast on August 18, 2022, preceding the convective event and evaluated during the critical intensification window (07h00-08h00). We compare this hybrid quantum model to classical CNN-LSTM and CNN-LSTM-Transformer architectures using three complementary metrics : Root Mean Squared Error (RMSE), Structural Similarity Index (SSIM), and Wasserstein Distance. The quantum model demonstrates superior robustness to input noise and adversarial perturbations (FGSM), maintaining spatial coherence and prediction stability under degradation. These findings highlight the capacity of quantum circuits to encode more resilient representations for meteorological inference.This study offers a concrete application of hybrid quantum-classical neural architectures in the domain of extreme weather forecasting and paves the way for future integration of Topological Data Analysis (TDA) to assess the preservation of topological features in quantum predictions.</div
Analysing Geothermal Heat Exchangers Using Comsol Non- Isothermal Pipe Flow Model
No full textInternational audienc
Visco-elasto-plastic characterization and modeling of a wet polyamide laid-strand sub-rope for floating offshore wind turbine moorings
No full textInternational audiencePolyamide 6 fiber ropes are of interest for floating offshore wind turbine mooring lines but could exhibit complex mechanical behavior during loading at sea, such as creep, relaxation, variable dynamic stiffness or visco-plasticity. There is a need for a model that could be introduced into finite element analyses to predict this complex response; it should also describe the effect of the loading history. This paper presents a visco-elasto-plastic behavior model based on four dashpot-ratchet-spring elements that allow a precise description of polyamide 6 rope behavior. An identification method, using a multi-relaxation test, is described. It has been implemented in a finite element analysis software and validations are made by comparing the model results to the experimental data. The present work is the result of an extensive effort initiated by the collaborative research project POLYAMOOR and continued by the MONAMOOR project, both led by France Energies Marines
Deriving Stable Peak Models to Fit Complex XPS Data From Cu Contaminated Pt Electrocatalysts
No full textInternational audienceX‐ray Photoelectron Spectroscopy spectra peak models, designed to partition photoemission signals emanating from different elements or chemical states within an atom, are fitted to data limited to an energy interval over which inelastically scattered photoemission signal can be estimated. While the choice of background approximation and line shapes of components to the peak model requires careful consideration, the energy interval used to define the data to which the peak model is optimized has a significant impact on the final peak model. The relationship between the background intensity and data intensity at the start and end of the energy interval dictates the line shapes used in the peak model. In this work, we devise a method to peak fit a complex overlapping Cu 3p and Pt 4f XPS peak structure to perform the elemental quantification. We first use an Al 2s peak to illustrate how background curves approach data at the limits of the energy interval over which the background is defined, influencing the analysis of XPS spectra. Next, we demonstrate the nature of interactions between specific line shapes (Voigt and pseudo‐Voigt profiles) suitable for photoemission peaks and a specific background curve (Shirley) and a peak model is presented that includes components to the peak model that accommodates background intensity during fitting of the peak model to data. The peak model allowed for quantification of the contributions of Pt 4f peaks emanating from the substrate that exhibits strong asymmetry in the presence of the inhomogeneously distributed Cu species, mostly of Lorentzian character
La trayectoria singular de una hoja de maíz
No full textInternational audience«La trayectoria singular de una hoja de maíz» es un cortometraje basado en una investigación de Francesca Cozzolino sobre la producción de objetos de diseño a partir del cultivo del maíz en el estado mexicano de Puebla. La película permite a la investigadora presentar su trabajo de campo y los datos producidos como parte de su investigación etnográfica en forma de narración visual que vincula un contexto local (la desaparición del maíz nativo de la región semiárida de la Mixteca mexicana) con un acontecimiento de la historia global contemporánea (la firma del NAFTA, el acuerdo de libre comercio). A través de una voz en off —la voz de las mazorcas de maíz nativo—, la antropóloga relata cómo el diseñador mexicano Fernando Laposse, en su búsqueda por un enfoque sostenible y local del diseño así como por un medio para apoyar a una comunidad agrícola en dificultades, logró convencer a un grupo de familias del pequeño pueblo de Tonahuixtla, en el estado de Puebla, para que trabajaran la tierra siguiendo los principios de la permacultura (milpa) y, posteriormente, se encargaran de transformar, mediante procesos semimecánicos, las hojas de maíz que cultivaban en un elegante material de recubrimiento: el Totomoxtle. La voz en off, apoyada por procesos de montaje y animación 2D, se basa en los documentos fotográficos, de vídeo y sonoros de la investigadora, así como en la creación de imágenes en movimiento para dar a entender el enfoque del diseñador y las cuestiones ecológicas que este caso plantea a mayor escala. Construida a tres voces, esta película reúne a una antropóloga, Francesca Cozzolino, una documentalista especializada en el registro visual de actividades profesionales colectivas en el ámbito de las ciencias, Coralie Maurin, y una diseñadora gráfica, Juliette Nier, que trabaja con herramientas de animación 2D para abordar fenómenos de confrontación con realidades difíciles de aprehender, a veces incongruentes o complejas de explicar. La película explora los códigos de la ficción, el documental y la animación para revelar al espectador un proyecto situado en los límites de la tradición inventada y la innovación técnica. En una perspectiva más amplia, el caso de Totomoxtle nos lleva a plantearnos la cuestión de la concepción y la transmisión de una técnica, en un contexto en el que se enfrentan las sutiles hibridaciones culturales, económicas, políticas y ecológicas que caracterizan nuestros mundos contemporáneos
Quand le privé « fabrique » des « hauts fonctionnaires »: La construction politico-institutionnelle d’une frontière poreuse entre « public » et « privé » au Pérou
No full textInternational audienceThe corruption scandals of recent years in Peru have highlighted the existence of a politicoadministrative system based on circulations between ‘public’ and ‘private’ spaces. This article invites us to look at these revolving doors beyond the single issue of conflict of interest, to consider what they reveal about the struggles and power relations that seek to preserve, or on the contrary to change, the legitimate characteristics of those who hold state power. More specifically, it seeks to link the study of these circulations back to the social and political environment in which they took place. The article also stresses the need to take account of the broader sociological dimensions underlying these movements, pointing out that strategies for professionalisation (and movement) are not the same depending on the social origin of civil servantsLes scandales de corruption de ces dernières années au Pérou ont remis en lumière l’existence d’un système politico-administratif fondé sur des circulations entre espaces « publics » et « privés ». Cet article invite à appréhender ces revolving doors au-delà de la seule question du conflit d’intérêts pour s’intéresser à ce que celles-ci révèlent des luttes et rapports de force destinés à préserver, ou au contraire faire évoluer, les caractéristiques légitimes des détenteurs du pouvoir d’État. Plus particulièrement, il s’attache à réancrer l’étude de ces circulations à l’environnement social et politique les permettant. De même, l’article insiste sur la nécessité de rendre compte des dimensions sociologiques plus larges qui sous-tendent ces circulations, rappelant que les stratégies de professionnalisation (et de circulations) ne sont pas les mêmes en fonction de l’origine sociale des fonctionnaires