In the field of cultural heritage, various data describe the state of the monument (survey data and scientific imaging, mappings of degradations, photographic collections, historical archives, analysis documents, coring, etc.). For the difficulty to collect, compare, analyze and validate data prior to restoration, this project aims to mobilize various disciplines (architecture, conservation, mechanics, informatics) to define a prototype of chain for the processing of information (including metrics and spatial analysis of surfaces, geometric models of structures, heterogeneous documentary sources, etc.). The objective is to design and develop an open and extensible software platform for the capitalization and the management of knowledge that enhances the comprehension and analysis of degradation phenomena affecting historic buildings. This project belongs to a highly multidisciplinary approach, and aims to support, in a rational way, the set of technical features (leaning on the "technological blocks" already developed by the consortium partners). Moreover, it aims to integrate them within a methodological reflection related to scientific questions raised by real objects of study. In terms of computational modeling, this project presents two innovative aspects: on one side, the idea of ??linking (and of bringing near) the phase of acquisition of spatial data to the one of data analysis and interpretation, on the other side, the ambition to develop analysis supports (morphology of the building, surface state, structural behavior) interconnected in a system conceived for the semantic characterization, based on mechanisms of distribution / spread (multiscale and multi-projection) of concepts structured according to an ontology specific to cultural heritage domain.

The demonstration of safety and the extension of the lifetime of complex industrial devices (nuclear...) are based on the periodic non-destructive testing (NDT) of welded parts. When there are thick welds (30 to 70 mm), in austenitic stainless steel, the ultrasonic method for defect detection is the only one possible. It is however complex because the heterogeneous and anisotropic nature of these thick multi-pass welds induces strong perturbations in the propagation of the acoustic beam which distort the diagnostic. The best (non-destructive) solution to overcome this difficulty is obtained by modelling the ultrasonic propagation, but this requires the detailed description of the real crystalline structure of the weld. The current 2D weld models, except LMA’s work, provide either a simplified description of the crystallographic growth, based on a symmetry assumption, or a more realistic description, but at the cost of high instrumentation and computation time. Moreover, no model exists for a weld made in position, when the solidification is also governed by gravity. The objective of the project is to produce a realistic 3D model for welds made with GTAW process in all positions, from minimalist input data (those given by the DMOS) and with a calculation speed compatible with industrial needs. Gravity induces inclinations of the texture not only in the direction perpendicular to the weld, but also in the welding direction. The transition from 2D to 3D is therefore not a simple evolution or adaptation of MINA 2D, because the gap is very important. The study will be progressive: some mock-ups will be manufactured for a narrow chamfer (U-type) which allow a stacking of a single pass per layer, and open chamfer (V-type) geometry, in vertical-up and horizontal groove welding position. Specific instrumentations (embedded camera, optical microscopy, EBSD) will help us to understand the solidification kinetics and the grain growth, and then to create the model, the challenge being linked to the various length scales present (weld, grain, dendrite). The objective is to determine a link between the pool shape (gravity, welding energy, ...), the thermal gradient (part temperature, chamfer, preheating, ...), and the crystal growth (crystal competition, ...). The orientation of the grains will be ultimately calculated from information voluntarily restricted to the welding notebook which describes the welding procedure (geometry of the chamfer, sequence of passes, etc.), to be in adequacy with the industrial practice, which cannot afford to instrument each welding carried out in a complex way. The micrographs simulated by the model will be compared to the real micrographs and will thus allow to validate it. A second validation will also be sought by comparing the ultrasonic propagation predictions obtained by associating the MINA 3D model with a 3D ultrasound propagation model, with experimental data. The prediction of the deviations and divisions of the ultrasonic beam will then be mastered, bringing a significant improvement of the ultrasonic testing. The MINA 3D project perfectly fits with the research axis B.4. One innovation concerns the increase in knowledge of the material, but the main innovation is in the application, and therefore in the consequent improvement of the potential of NDT by ultrasound. The 6 partners of the project are the best French specialists in the field and used to work together.

Plant residues are an abundant source of renewable matter, but require targeted dissociation at the tissue scale for the design of high-quality products. This is a huge scientific challenge that crucially depends on the variety of the compositions and histological structures of plant tissues as well as the complex physics of grinding, involving the poorly-understood flow of breakable particles of various shapes and properties. The ambition of this project is to elaborate a generic multiscale approach for realistic modeling of plant comminution accounting for both cellular and granular microstructures of plant residues. This bottom-up approach will proceed from the mechanical and physicochemical interactions at the scale of the relevant constituents (cells, envelopes, organs...) to model intercellular dissociation with the goal of developing single-particle fracture laws that will be validated experimentally and included in dynamic simulations of a large number of particles at the process scale. The methodology that we propose is based on state-of-the art computational (Peridynamics, Discrete Elements) and experimental (histology, multispectral imaging, tomography, milling) approaches. It will be organized in three work packages dealing with 1) Mechanics of fracture at the cell/tissue scales, 2) Fracture behavior at the scale of a single plant residue particle, and 3) Fragmentation process of plant material. The consortium is composed of three partners with complementary expertise, involving early-career and confirmed researchers. The project will benefit from the longstanding experience with tissue characterization methods and grinding of vegetal powders in Montpellier and X-ray and neutron imaging in Grenoble. The originality of PlantCom lies in its multiscale and cross-disciplinary nature, bridging powder process with fracture mechanics and the rheology of granular materials, to elaborate a physics-based toolkit for plant comminution.

In the last past years, Additive Manufacturing (AM) processes have been intensively developed leading to a revolution in many industrial sectors. These processes offer the possibility of developing parts of complex geometry and high mechanical strength, with short manufacturing times and with important raw material saving. However, conventional metallic AM processes suffer from the prohibitive cost of raw materials, in a powder form, and low deposition rates, increasing manufacturing times and limiting the dimensions of the produced parts. In this context, the MACCADAM project aims to promote the industrialization of a new arc-metal additive manufacturing process derived from welding and based on the deposition of successive layers of a metallic wire melted with an electric arc. This original process differs from other traditional AM processes by allowing high material deposit rates and the use of low cost and easy to use massive products. MACCADAM proposes to solve several issues that still limit the use and diffusion of this innovative process. The aim of this project is to : 1) identify potential applications of this new process based on a comparative analysis of the respective characteristics of the arc-metal process and the other AM processes; 2) identify the process parameters (electric parameters, protective gas, layer stacking strategy ...) leading to optimal geometrical characteristics and limiting the distortions due to residual stresses, for two materials chosen for their industrial interest (316L stainless steel and TA6V titanium alloy); 3) carry out a microstructural and fatigue resistance characterization of the materials in order to assess the parts mechanical properties according to the manufacturing parameters set; 4) model the solidification process of the deposits in order to predict the microstructures and associated mechanical behavior with numerical simulations. MACCADAM gathers academic and industrial partners specialized in the fields of additive manufacturing processes (LMGC, Poly-Shape), materials characterization (ICA, LGP, LMGC) as well as modeling and numerical simulation of forming and manufacturing processes of metallic materials (CEMEF). Ultimately, MACCADAM intends to promote the diffusion of this new process in the industrial world, within a controlled framework, to guarantee the production of high performance parts at a reduced cost.

The focus of DUINTACOS is to achieve a deep understanding of interface formation in fiber reinforced thermoplastic tapes in order to reduce voids and obtain high quality composite structures. To have a global overview of these phenomena and a real impact on composite applications, different “interface systems” constituted by different materials will be considered: carbon fiber reinforced poly (ether ether ketone) tapes, biodegradable flax/polylactic acid tapes and newly formulated recycled carbon reinforcement impregnated in recycled household polymers (polypropylene, polyethylene terephthalate…). DUINTACOS will thus focus on tapes constituents first, and then on the methodology to be applied to manufacture tape demonstrators. This approach will allow modifying physico-chemical and mechanical properties of constituents and thus the resulting interfacial properties. Constituents properties will be characterized, especially in terms of fibers surface energy and molten polymer surface tension, as well as dispersive and polar components of both constituents at different temperatures. Key parameters affecting the adhesion phenomena at the local fiber/matrix interface will be then assessed (first objective). The dynamic wetting of molten polymer on fibers will also be investigated at the microscopic scale of single fiber and at the mesoscopic scale of tape. This phenomenon of impregnation occurs with temperature and does not depend only on the intrinsic properties of constituents. Dynamic wetting also depends on the interaction between the fluid and the fiber during the flow at the microscopic scale, and on the arrangement and morphology of fibers in the yarn at the mesoscopic scale (second objective). Moreover, once wetting of fibers by molten polymer has occurred, the crystallization at the local scale of fiber/matrix interface and the induced microstructure will be studied, determining the relationships between polymer wetting, adhesion at the interface, consolidation, and possible polymer degradation (third objective). The induced mechanical properties of interface at the local scale will also be estimated, combining different methods (fourth objective). Finally, the overall aim will be to completely overcome the issue of micro-porosities and defects occurrence in tapes controlling the relationships between fiber/matrix interface formation, its induced microstructure and mechanical properties. Issues addressed in this project have been organized in four objectives of “Deep Understanding” (DUO) that will be achieved completing relative work-packages (WP). This project relies on a fundamental experimental study to allow a better understanding of prevalent mechanisms of fiber/matrix interface adhesion and void formation that occur during composite manufacturing at the scale of fiber reinforced thermoplastic tape. These mechanisms are not yet well known and need to be investigated rigorously. The originality of DUINTACOS consists in studying interface formation and consolidation, considering high temperatures and the consequent cooling at microscopic and mesoscopic scales, to simulate the process conditions. This study thus requires the development of original experimental methods. Another originality of the work is to consider a large selection of materials and semi-products to have a global view of possible mechanisms occurring at the composite interface. The ambition is to fully understand mechanisms of voids formation in order to obtain high quality interfaces in fiber reinforced thermoplastics, achieving a maximal material health and thus high quality composite structures, also for biodegradable and recycled ones.