To support the European Union’s 2050 climate neutrality goal and the 2019 European Green Deal, the industrial sector must reduce its environmental footprint, especially in high-energy manufacturing processes such as laser cutting. While fibre laser cutting is widely adopted for its efficiency, the literature remains focused on first-generation CO₂ lasers, and lacks multicriteria assessments integrating environmental, economic, and technical aspects. To address these gaps, this study proposes a framework based on an environmental analysis, which guides the identification and evaluation of concrete alternative production solutions. An environmental assessment of a fibre laser cutting process was conducted using the Product Environmental Footprint method. Results show that raw material consumption dominates climate change, followed by assist gas, electricity, and metal waste. Three alternative solutions were examined: internal nitrogen generation, compressed air, and a hybrid solution combining production with compressed air and nitrogen. Nitrogen generation doubled costs and was rejected. Compressed air offered the best environmental gain but had technical limits. The hybrid solution proved the most balanced. It reduced assist gas impact on climate change by 62

Laser cutting is an old and multi-physical process that was quickly adopted by the metallurgical industry. However, this fast industrialisation has had a significant impact on quality control. Several studies have been carried out to characterise and minimise different types of cutting defects. Reviews published between 2008 and 2022 highlight that research often focuses on single-criterion ___quality' approaches, aiming to minimise specific defects such as the Heat-Affected Zone, surface roughness, or kerf geometry. Consequently, efforts have been directed at optimising specific aspects of quality rather than adopting a complete approach. Furthermore, these reviews reveal that cutting quality can be enhanced through the careful selection of laser manufacturing parameters and part parameters. However, while parameters such as material and thickness have been investigated, the influence of part morphology on cutting quality remains underexplored.___ Although some studies have examined the effects of material and thickness, part morphology is often limited to simple segments with varying cutting lengths or angles. While other research has investigated the impact of angle size on cutting quality, no established method exists to systematically determine the influence of each part morphology on cutting quality.______ In response to this gap, the present study proposes to evaluate the criticality of cutting defects, as defined by existing standards, across various part morphologies using a method adapted from Failure Modes, Effects, and Criticality Analysis (FMECA). The objective is to develop a global approach that examines the influence of all morphologies on all types of cutting defects. An industrial application shows that cutting defects, particularly thermal ones, are strongly influenced by morphologies, while thickness affects them irregularly. Improvement priorities target critical defects shaped by both factors. Burrs and adherent slag are critical in angles and arcs, while segments, often used in studies, are less sensitive._________ These observations lead to the definition of design limits. This method offers a detailed analysis of the influence of design data on quality, providing practical tools for improving industrial processes._________

Laser cutting is an established, multi-physical process widely adopted by the metallurgical industry. However, this fast industrialisation has had a significant impact on quality control. Reviews from 2008 to 2022 primarily focus on single-criterion quality approaches, targeting defects like the Heat-Affected Zone, surface roughness, or kerf geometry, rather than adopting comprehensive methods. In addition, these studies show that cutting quality can be improved by selecting laser manufacturing parameters and part parameters such as thickness or material. However, the influence of part morphology remains underexplored. Following this observation, this study proposes a generic and complete method adapted from the Failure Modes, Effects and Criticality Analysis, allowing the evaluation of the criticality of all cutting defects in a part. It focuses on six laser cutting defects defined in an international standard and three types of morphology: arcs, angles and segments. The aim is to establish a holistic approach linking morphologies to all defect types. Industrial application reveals that thermal defects are highly influenced by morphology. Burrs and adherent slag are particularly critical in arcs and angles, while segments are less sensitive. This analysis establishes design limits and offers practical tools to improve industrial laser cutting through detailed quality assessments.

Laser cutting, a long-established multi-physical process, has been widely adopted in the metallurgical industry, but its rapid industrialization has impacted quality control. Reviews from 2008 to 2022 primarily focus on single-criterion quality approaches, targeting defects like the Heat-Affected Zone, surface roughness, or kerf geometry, rather than adopting comprehensive methods. In addition, these studies show that cutting quality can be improved by selecting laser manufacturing parameters and part parameters such as thickness or material. However, the influence of part morphology remains under-explored. Research often limits morphology to simple segments with varying lengths or angles, neglecting a systematic analysis of its impact. To address this gap, this study evaluates the criticality of six cutting defects, as defined by existing standards, across three morphologies (arcs, segments, and angles) using an adapted Failure Modes, Effects, and Criticality Analysis method. The aim is to establish a holistic approach linking morphologies to all defect types. Industrial application reveals that thermal defects are highly influenced by morphology, with burrs and adherent slag being critical in arcs and angles. Segments, however, show less sensitivity. This analysis enables the definition of design limits and provides practical tools for improving industrial laser cutting processes through detailed quality assessments.

Nowadays the development of innovative processes is a major challenge for industries which want to prototype functional workpieces. Incremental sheet forming (ISF) is a good alternative for sheet metal prototyping to ensure flexibility, accuracy of the part produced, and cost effectiveness. A derived process, the Water Jet Incremental Sheet Forming (WJISF), has been undergoing development since 2001 and this paper purpose to give its state of the art. Different eclectic industrial fields could be concerned by WJISF process: automotive, micro-electronics, medical, and aerospace industry, for example. As the ISF process, the WJISF device needs a multi-axial machine, but it also needs a pressure pump with a sufficient flow rate and pressure. In an environmental point of view, this process can be seen as a "green" one giving that the water can be recycled and there is no lubricant. A general methodology has been defined to rigorously investigate this process and focus on researchers' teams, technological feasibility, numerical simulations, machine-tool uses, and real parts manufacturing. The study presented here provides summarizing evidence, especially technological windows, which give quick view of the actual knowledges and will help scientists and industrials to find WJISF parameters related to their needs. A lot of simple tests have been carried out with numerical and experimental comparisons. Nevertheless, few real parts have been manufactured, and the complex shape obtained by WJISF remains a scientific field to explore.

Spectral induced polarization (SIP) has the potentialfor monitoring reactive processes in the subsurface. While strong SIPresponses have been measured in response to calcite precipitation,their origin and mechanism remain debated. Here we present anovel geo-electrical millifluidic setup designed to observe microscalereactive transport processes while performing SIP measurements.We induced calcite precipitation by injecting two reactive solutionsinto a porous medium, which led to highly localized precipitates atthe mixing interface. Strikingly, the amplitude of the SIP responseincreased by 340% during the last 7% increase in precipitate volume.Furthermore, while the peak frequency in SIP response variedspatially over 1 order of magnitude, the crystal size range was similaralong the front, contradicting assumptions in the classical grainpolarization model. We argue that the SIP response of calcite precipitation in such mixing fronts is governed by Maxwell-Wagnerpolarization due to the establishment of a precipitate wall. Numerical simulations of the electricfield suggested that spatial variationin peak frequency was related to the macroscopic shape of the front. Thesefindings provide new insights into the SIP response ofcalcite precipitation and highlight the potential of geoelectrical millifluidics for understanding and modeling electrical signatures ofreactive transport processes

Summary Spectral induced polarization (SIP) has shown potential to detect subsurface reactive transport processes. However, previous laboratory experiments could not associate the SIP response with the temporal development and spatial distribution of reactive transport processes in detail due to the opaque nature of porous media. We developed a novel experimental setup that consists of a millimeter scale 2D transparent porous medium and electrodes for SIP measurements to visually observe reactive transport processes down to the pore scale while performing SIP measurements (i.e. a 2D millifluidic setup). We used this setup to investigate the SIP response of calcite precipitation (CaCO₃). The image analysis and SIP measurements highlight that the SIP response does not necessarily represent the total mass of calcite precipitation in the measurement region. In addition, we numerically simulated the electric field distribution based on the observed calcite precipitation. The results suggested that the heterogeneous distribution of calcite precipitation within the investigated volume had an important influence on the SIP response. Given the heterogeneous and localized nature of many reactive processes, these findings clearly demonstrate the importance of investigating sub-resolution reactive processes for SIP measurements. The proposed novel experimental setup was shown to be suitable for this purpose.

Abrasive water-jet manufacturing process can shape a lot of materials ranging from metals to glasses. It has a lot of advantages, as its low cutting forces, but remains quite difficult to control. Indeed, the process is leaded by the abrasive particle trajectories which depends on the water static pressure and many other parameters. The impact pressure on the work-piece is commonly modeled by a two Gaussian fit sum which are representative of the particles velocity distribution and the granulometry respectively. Today no studies based on discrete elements take into account the mixing chamber and the focal canon which are the two main steps of the abrasive water-jet tool constitution. In this preliminary work we propose to model the flow through the focal canon until the target impact by an original numeric granular approach. The Non-Smooth Contact Dynamics is an efficient method on a large range of simulation domains. In our case, we consider the water phase and the abrasive phase as two collections of distinct polydisperse elements. The masses are corrected and the contact interaction laws are adjusted to account for an equivalent fluid which similar mechanical properties. These two phases are mixed in a chamber and focalised through the canon, knowing water static pressure and abrasive mass rate. After the canon end the abrasive water-jet evolves in air and thus decelerates by friction. The tool-fluid adapts its geometric configuration from this kinetic energy decrease and impacts a target plane located at a known distance from the canon. Such a model is built on some classic process parameters as the water static pressure, the abrasive mass rate or the work-piece vs. canon distance, but it also naturally takes into account finer mechanical parameters as the abrasive granulometry or friction dissipation. Simulations gives interesting results of impact pressure distribution on the target work-piece with dynamic data of all the collection particles. More generally, this work final aim is to link elemental particle damage studies with a macroscopic wear prediction law.

An analytical model is developed to describe the phenomenon of giant photoexpansion in chalcogenide glasses. The proposed micro-mechanical model is based on the description of photoexpansion as a new type of eigenstrain, i.e. a deformation analogous to thermal expansion induced without external forces. In this framework, it is the viscoelastic flow induced by photofluidity which enable the conversion of the self-equilibrated stress into giant photoexpansion. This simple approach yields good fits to experimental data and demonstrates, for the first time, that the photoinduced viscous flow actually enhances the giant photoexpansion or the giant photocontraction as it has been suggested in the literature. Moreover, it highlights that the shear relaxation time due to photofluidity controls the expansion kinetic. This model is the first step towards describing giant photoexpansion from the point of view of mechanics and it provides the framework for investigating this phenomenon via numerical simulations.

Stirred bead mills used in industry allow to split up particules in suspension by agitating a milling medium. The multiple impacts may damage beads and thus reduce the stirred milling process efficiency. A discrete numerical approach including simple fluid effects is proposed and carried out in this paper to model and study finely the damage phenomenon. The simulation data allow to identify internal variables of the milling medium and to localize high energy zones. The order of magnitude of contact forces including fluid contribution will enhance the bead wear law.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Simulation et analyse d un broyeur à billes par éléments discrets Romain Laniel, Madina Tchikou, Jean-Christophe Sangleboeuf

Nous proposons deux types de modélisations adaptées au calcul de changements de phase allotropiques.Seules les conséquences induites par la variation de volume sont prises en compte, de façon identique à ce que l'on trouve dans les modèles de Greenwood et Johnson.Dans les années 80, Leblond proposa un modèle basé sur la croissance d'une sphère de phase dure dans une matrice plus molle afin de déterminer les lois d'évolutions élastoplastiques.Dans une première partie, nous proposons d'étendre le modèle de Leblond en prenant également en compte la croissance de la phase molle dans une matrice de phase dure, ce qui correspond à la fin de transformation dans le processus de refroidissement.La seconde partie est consacrée à une modélisation plus fine où l'on représente explicitement le front de transformation par fonctions de niveau.Les équations de propagation du front sont résolues par éléments finis et la simulation mécanique utilise la méthode des éléments finis étendus afin d'éviter les coûteux remaillages.

A geomaterial called TexSol and composed of sand and wires was investigated by numerical experiments in order to determine its geometrical and mechanical parameters, such as tortuousness of the wire, anisotropy and characteristic length. This stage is essential for studying a material with an obvious non-local behavior. Investigations by discrete elements highlighted that the characteristic length was dependant on the loading level. These simulations provided access to variables that standard physical experiments cannot provide. Some parameters of a continuous model of TexSol were identified through discrete numerical experiments using a classic procedure. The other parameters were determined by finite element method updating.

Two methods are proposed in the following in order to calculate allotropic phase changes. We take into account only the consequences of the volume variation in a same way as in the Greenwood and Johnson's works. In the 80's, Leblond proposed to identify the elasto-plastic evolution law by considering the growth of a hard spherical inclusion in a soft matrix. In the first part, we propose to extend the Leblond's model by considering also the growth of the soft inclusion in the hard matrix that is closer to the end of a cooling transformation. The second part is dedicated to a finer modeling where the phase front is explicitly represented by level sets. The front propagation equations are solved by finite elements and the mechanical simulation is based on the eXtended Finite Element Method in order to avoid costly remeshing.

Indentation and scratching tests are carried out on a ZrCuAlNi bulk metallic glass. The bonded interface technique is used to characterize the plasticity mechanisms underneath the indentation. Finite-element analyses are conducted with a Drucker–Prager behaviour law to challenge the indentation experimental data. The relevance of the bonded interface technique, in terms of quantitative evaluation, is discussed. It is also reported that the angle value, for which radial bands intersect at the surface or underneath it, is not a constant value and depends on the indenter geometry. Finally, it is shown that a simple Drucker–Prager model can describe most of the indentation mechanical response but fails in predicting completely the indentation morphology.

The aim of the study is to build discrete numerical models of a wire-reinforcement for geomaterials to perform multi-scale investigations. Non Smooth Contact Dynamics is used to carry out large or small strain mechanical tests on a granular sample. Different numerical experiments distinguish the main reinforcement micro-mechanisms and their consequences for macroscopic behavior.