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Que ce soit dans une problématique de séchage, ou de diagnostic des structures, la caractérisation de l’eau dans le bois est un sujet qui préoccupe les chercheurs depuis des décennies, car cette dernière a une forte influence sur les caractéristiques mécaniques de ce matériau. Ainsi, de nombreuses études ont menées à la création de modèles de transfert hygrothermique ont été conçu, prenant en compte les transferts de vapeur et d’eau liée et/ou libre. [WUFI, TRANSPORE, …] Toutefois le nombre important des paramètres de diffusions dépendants de la température et de la teneur en eau conduit souvent à simplifier ces dépendances.

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The investigations that are made on a building for conservation purposes need an importantwork that is transcribed in a variety of numerical and printed data: surveying data andscientific imagery, damage mapping, photographic collections, historical archives, physicaland chemical data etc. Given the difficulty to collect, compare, analyse and validate dataprior to restoration, the approach we present aims to mobilize various disciplines(architecture, conservation, mechanics, and computer sciences) to define a novelinformation processing chain including metric surveys, analysis of surfaces, geometricmodels of structures, heterogeneous documentary sources management, temporal data, etc.By the way of MONUMENTUM project which is an on-going research project (2013-2017) funded by ANR (French National Agency for Research), we are designing anddeveloping an open and expandible web platform for the capitalisation and the managementof knowledge needed for the understanding and analysis of degradation phenomenaaffecting historic buildings. This objective requires the definition of a common andcontinuous process that establish a technological and conceptual interconnection betweenthe stages of 3D digitization, semantic annotation and structuring of the geometric model(including multi-layers analysis of surfaces), characterisation of the state of the buildingand management of restoration actions. Based on three case studies that presentconservation issues on stones (Castle of Chambord and Caromb’s church in France) andwall paintings (Notre-Dames des Fontaines’ chapel in France), it concerns the image-basedmodellingof architectural heritage, the development of a 3D information system for the management of conservation data and also a numerical modelling tool (FEM-DEM) for thephysical and structural analysis.

Commentaires: Acknowledgements: This ongoing study is financed by ANR (French National Agency for Research). The authors thank all the other colleagues (and more especially S. Janvier (PRISME), S. Boularand (CICRP), E. Gattet, F. Guéna and A. Pamart (MAP) and students (and more especially A. Benard, F. Peteler, A. Manuel, T. Messaoudi), that are/were involved in this project and allow its development.

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Ref HAL: hal-01348721_v1
DOI: 10.1016/j.jcp.2016.06.041
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This paper constitutes an extension of the work of Mendez, Gibaud & Nicoud: An unstructured solver for simulations of deformable particles in flows at arbitrary Reynolds numbers, Journal of Computational Physics, 256(1): 465-483 (2014), for three-dimensional simulations of deformable membranes under flow. An immersed thick boundary method is used, combining the immersed boundary method with a three-dimensional modeling of the structural part. The immersed boundary method is adapted to unstructured grids for the fluid resolution, using the reproducing kernel particle method. An unstructured finite-volume flow solver for the incompressible Navier-Stokes equations, is coupled with a finite-element solver for the structure. The validation process relying on a number of test cases proves the efficiency of the method, and its robustness is illustrated when computing the dynamics of a tri-leaflet aortic valve. The proposed immersed thick boundary method is able to tackle applications involving both thin and thick membranes/closed and open membranes, in significantly high Reynolds number flows and highly complex geometries.

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Ref HAL: hal-01517290_v1
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Un modèle de mélange fluide/grains est présenté. Pour la phase granulaire, la dynamique des contacts est calculée à l'échelle des grains. À une échelle supérieure, les équations de Navier-Stokes/Brinkman modélisent l'écoulement du fluide dans un milieu poreux. Ces équations sont résolues au moyen d'une méthode éléments finis. Cette approche permet de simuler dans un même modèle une transition continue entre, à concentration élevée de grains, un régime de Darcy et, à faible concentration, un écoulement fluide classique.

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