Appel à Candidature Thèse : Analysis and numerical modeling of dynamic fragmentation processes in brittle materials over a wide strain rate range
Contact
Partenaire(s)
Télécharger
- PhD proposal 2023-2026 (application/pdf, 384Ko)
Required skills and duration
Results in master: Outstanding results
Fields: Mechanics, materials, space and aircraft industry
Nationality: No specifications
Start of PhD thesis: from October 1st, 2023 to December 1st, 2023

Appel à Candidature Thèse : Multiscale study of the temperature-dependent behaviorof Calcium-Silicate-Hydrate
Contact
Télécharger
- Multiscale study of the temperature-dependent behavior of Calcium-Silicate-Hydrate (application/pdf, 218Ko)
Required skills and duration
- Experience with (or motivation to learn) molecular dynamics and modern computa-
tional physics.
- Experience with (or motivation to learn) programming and high-performance comput-
ing.
- Advanced English for scientific communication.
3 years starting from October 2023
Application process and References
Majdouline Laanaiya - majdouline.laanaiya@univ-grenoble-alpes.fr or/and Pr. Stefano
Dal Pont - stefano.dalpont@3sr-grenoble.fr before April 30th, 2023.
References :
[1] D Dauti et al. ‘Modeling concrete exposed to high temperature: Impact of dehyd-
ration and retention curves on moisture migration’. In: International Journal for
Numerical and Analytical Methods in Geomechanics 42.13 (2018), pp. 1516–1530.
[2] Hani Cheikh Sleiman. ‘Contribution of neutron/X-ray tomography for the drying
modeling of cohesive porous media’. PhD thesis. Université Grenoble Alpes, 2021.
[3] Mohammad Javad Abdolhosseini Qomi et al. ‘Advances in atomistic modeling and
understanding of drying shrinkage in cementitious materials’. In: Cement and Con-
crete Research 148 (2021), p. 106536.
[4] Majdouline Laanaiya and Ali Zaoui. ‘Piezoelectric response and failure behavior
of cement paste under external loading’. In: Cement and Concrete Research 139
(2021), p. 106257.
Appel à Candidature Thèse - Projet ANR DRYSALT
La thèse est prévue en deux étapes principales :
1) modélisation et simulation de la croissance d’une structure de sel en milieu poreux modèle non-déformable,
2) modélisation et simulation du phénomène de soulèvement (déplacements des grains d’un milieu granulaire induit par la cristallisation) en combinant méthode des éléments discrets (DEM) et simulations des phénomènes de transport et de cristallisation par des techniques de volumes finis ou réseau de pores. Les différents développements numériques seront implémentés dans Yade, un logiciel open source développé principalement au laboratoire 3SR.
Télécharger
- Appel à Candidature Thèse - Projet ANR DRYSALT (application/pdf, 347Ko)
Postdoc Position Durability of microbial-induced calcite precipitation Study of reactive flows in 2D model systems and in 3D soil columns using X-ray nano-tomography
Microbial-induced calcite precipitation (MICP) is a process increasingly used to reinforce structures and soils, and appears to be a relevant alternative to conventional techniques based on the injection of manufactured materials, being more environmentally friendly and consuming less energy. Indeed, it reinforces the bond contacts between grains after injection of bacteria that accelerate the natural process of calcium carbonate precipitation (CaCO3). A striking example is that a non-cohesive sand can be turned into a highly cohesive medium. Since the recent proof of concept made by Whiffin [1] and Mitchell and Santamarina [2], studies have demonstrated that calcite precipitation induced by bacteria activity is effective at large scale [3], and has a broad spectrum of applications, including internal erosion of hydraulic structures, liquefaction of soils during earthquake, landslides, or crack closure. Studies have focused on the effect of the process parameters : bacteria concentration [4], calcium concentration, pH, temperature, and water saturation of the media [5] on the calcite distribution in pores and on the mechanical properties of the improved media [6], [7]. Moreover, our teams have recently demonstrated the importance of the microstructure at the contact scale on the mechanical behaviour [8]–[11].
Nevertheless, for engineering applications, the assessment of the durability of the reinforcement process by MCIP is a concern. In particular, it is important to be able to predict how evolve the mechanical properties of a reinforced medium when it is submitted to acid conditions, which will cause the dissolution of calcite [12] and weakening of the structure.
Post doc program
The goal of this project is to characterize the evolution of the microstructure in reinforced media in real time, when exposed to an aggressive environment. In particular, a focus will be made on the contact surface area and the crystal morphology evolution through time.
The post-doc will have to develop experiments in 2D model porous media to characterize the dissolution process with a relevant instrumentation including high-resolution imaging. Then, the dissolution conditions used in the 2D experiments will be transposed in 3D soil columns to perform time-lapse 4D nano-tomography imaging experiments using the high spatial and temporal resolution available at synchrotron facilities (ESRF).
The expected results are a better understanding of processes associated to the decrease in mechanical properties induced by calcite dissolution.
Location and practical aspects
The successful applicant will be hosted by the laboratory 3SR (Grenoble) in the “CoMHet” team. He/she will work under the supervision of Antoine Naillon and Catherine Noiriel (laboratory Géosciences Environnement Toulouse), and in collaboration with Christian Geindreau and Fabrice Emeriault.
The position is a 1-year contract with the opportunity to have some extended months.
The post-doc will start as soon as possible, from January 2023.
The gross salary will be around 2919 €/month depending on the experience of the applicant, equivalent to a net salary of around 2346 €/month.

L’équipe CoMHet s'agrandit
Antoine Naillon
Mehdi Bouzid
Mehdi Bouzid est aussi en charge des séminaires au laboratoire en collaboration avec Emmanuel Roubin.

PhD Position : 3D mechanics of cells in complex fibrous media
physiological/pathological phenomena such as wound healing, cancer metastasis or
embryogenesis. The aim of this project is to precisely investigate cell migration in
biological networks by studying the interactions between cancer cells and the
surrounding fibrous medium. Therefore, the main tasks of this thesis will be :
- A morphological characterisation of d ifferent fibr ous media (collagen networks at different concentrations) using confocal microscopy.
- The development of a stretching/shearing device to investigate fibre deformations of
- these networks subjected to various physiological loadings.
- The achievement of micromechanical stretching/shearing tests on Extra Cellular Matrix (ECM) samples. The data obtained will allow to build a micromechanical model for the macroscale visco hyperelastic mechanics of the soft fibrous ECM.
- The analysis of cell migra tion in the different ECMs. To understand the feedback between cell motility and network relaxation, observations will also be compared to numerical simulations.
- The determination of the local stresses exerted by cells using the micromechanical model developed.
The successful applicant will be hosted by the LIPhy (Interdisciplinary Laboratory of Physics – Grenoble, France – www-liphy.univ-grenoble-alpes.fr/) in the “MC2” team, and by the 3SR Laboratory (Soils, Solids, Structures, Risks – Grenoble, France – www.3sr-grenoble.fr/) in the “CoMHet” team. He/she will work under the supervision of Dr Laurent, Dr Verdier at the LIPhy and Dr Bailly at 3SR Laboratory. The PhD fellowship offer is available starting October 2021 for a period of 3 years. The gross salary will be 1787 €/months, equivalent to a net salary of 1414 €/month.
Qualifications of the applicant
The PhD candidate should have academic backgrounds in cell biophysics and mechanobiology, with a strong motivation to work at the interface between physics and biology. Specific skills in microscopic imaging, structural characterization of fibrous media and/or experimental mechanics of soft (bio)materials/gels will be strongly examined.
Applications
Interested candidates should send their CV, a cover letter and official transcripts of the last two years to /
Dr Valérie Laurent (
)
Claude Verdier (
)
Lucie Bailly (
)
Deadline for the application: 01/07/2021
Micro-mécanique de l’Interaction milieu granulaire-géogrille souple sous chargement complexe - Investigation expérimentale et numérique
Les mécanismes mis en jeu sont liés notamment à l’enchevêtrement et au désenchevêtrement des particules dans la maille, accompagnés de mécanismes de butée des particules dans la maille, de frottement des particules sur la grille et de changements de densité au niveau d’une zone d’interface dont l’épaisseur reste à définir. Tous ces mécanismes prennent naissance au niveau des contacts entres particules et grille.
L’exemple d’application qui sert de support à cette étude est celui du renforcement et de la stabilisation de sol par grilles géosynthétiques (géogrilles), qui sont actuellement largement utilisées dans les ouvrages géotechniques sans que leur action ne soit formellement identifiée (approche macroscopique et empirique issue d’essais de laboratoire ou d’essais sur ouvrages).
Le sujet sera abordé par une combinaison d’observations microstructurales et d’expérimentations à l’échelle de la maille (sous tomographie RX) et de modélisations numériques par éléments discrets (code Yade). Il s’agit en premier lieu d’observer, définir et comprendre les mécanismes mis en jeu lors des sollicitations appliquées, en traitant également le cas des sollicitations cycliques et les phénomènes induits (fatigue et dégradation).
Dans un premier temps, une campagne d’imagerie 3D sera faite par microtomographie RX sur plusieurs échantillons de taille adaptée à la géométrie du problème : on considérera en particulier les cas avec et sans grille, des milieux granulaires modèles composés de sphères de taille très voisines ou présentant une distribution large de taille de grains de forme plus anguleuse, des tailles respectives de maille et de particules qui permettent de créer ou pas le phénomène d’interlocking.
Une reconstruction numérique de l’arrangement granulaire et de la grille permettra ensuite de générer des avatars numériques de ces échantillons qui seront utilisés dans le code Eléments Discrets Yade. Les simulations numériques prédictives du comportement de l’interface milieu granulaire – grille concerneront alors des sollicitations élémentaires (compression, cisaillement) monotones et complexes (en particulier cycliques). Il sera également possible de prendre en compte dans la loi de contact entre grains et entre grains et grille une dégradation des propriétés avec les cycles.
En parallèle de la mise au point et de la réalisation des simulations numériques, on se propose de concevoir des expérimentations mécaniques spécifiques réalisées sous tomographie RX de manière à évaluer la pertinence de la modélisation numérique dans sa description des mécanismes d’interaction matériau granulaire – grille. Quelques configurations ou cas de référence seront ainsi analysées de manière à s’assurer que la modélisation numérique reste bien proche de la réalité des phénomènes. On souhaite ainsi étudier à l’échelle des mailles de la grille les mouvements induits par un chargement appliqué (en particulier cyclique) simultanément à la prise d’images.
Au-delà de la compréhension des mécanismes mis en jeu et de l’identification des paramètres clés, on souhaite pouvoir proposer des éléments objectifs de choix pour le dimensionnement de la géogrille de renforcement ou sa mise en oeuvre et évaluer la capacité et les possibilités des méthodes numériques existantes à décrire, dans un calcul à l’échelle de l’ouvrage, le comportement et le rôle des renforcements.
- Formation initiale en mécanique et génie civil, idéalement en géomécanique/géotechnique, compétences avérées et intérêt pour la programmation et la modélisation numérique, notamment des phénomènes d’interaction sol-structure, une expérience en microtomographie RX / méthodes de traitement d’images / micromécanique des matériaux granulaires serait un plus.
- Niveau de français requis : A2
- Localisation : laboratoire 3SR, domaine universitaire de Saint-Martin d’Hères
- Concours contrat doctoral de l’ED IMEP2
- Date limite de candidature : 15/05/2021
- Date (prévisionnelle) de début de contrat : 01/10/2021
- Salaire brut 1758€/mois
- Contact : fabrice.emeriault@3sr-grenoble.fr
Analyse numérique du comportement des pieux en interaction avec le sol, sous chargement multidirectionnel cyclique
L’approche par une étude numérique telle qu’envisagée au cours de cette thèse nécessite principalement i) le développement d’un modèle numérique tridimensionnel prenant explicitement en compte le pieu, le massif de sol et l’interaction sol-pieu, ii) la mise en œuvre de lois de comportement du sol et de l’interface sol-pieu pertinentes au regard du chargement, iii) le développement de procédures de chargement complexe (chargement multidirectionnel dans les directions horizontale et verticale, chargement cyclique, voire dynamique). Un tel modèle permettra d’analyser finement le comportement du système et de mener des études paramétriques sur différents facteurs géométriques, géotechniques et de chargement, en vue de l’élaboration de méthodes de prédiction.
- Localisation : laboratoire 3SR, domaine universitaire de Saint-Martin d’Hères
- Concours contrat doctoral de l’ED IMEP2
- Date limite de candidature : 15/05/2021
- Date (prévisionnelle) de début de contrat : 01/10/2021
- Salaire brut 1758€/mois
- Contact : orianne.jenck@3sr-grenoble.fr
- Formation initiale en géotechnique/géomécanique (Master/Diplôme d’ingénieur),
- Compétences en modélisation numérique, en particulier sur les problèmes d’interaction sol-structure relatifs aux ouvrages géotechniques : maîtrise préalable d’au moins un logiciel/code de calcul dédié à ces problématiques,
- Bonne compréhension des modèles de comportement des sols,
- Aptitude à la programmation,
- Maîtrise de l’anglais (C1) et du français (A2).
PhD Position : Auto-organization and mechanical properties of self-healing composite gels
Localisation
Project summary
New generation of self-healing hydrogels composed of nanoparticles incorporated into a 3D bio-polymeric matrix (see figure) are revolutionizing medical implants technologies. However, the microscopic mechanisms controlling their self-assembly and at the origin of their mechanical properties remains poorly understood, which hinders a technological breakthrough.
This PhD research program aims at lifting this lock by combining complementary expertise of 2 labs in Grenoble: (i) cutting-edge computational techniques through large scale coarse-grained molecular dynamics simulations and experimental investigations of the mechanical behavior of heterogeneous materials at 3SR lab; (ii) physico-chemical formulation as well as structural characterization of hydrogels at CERMAV using NMR spectroscopy, Dynamic Light Scattering and Transmission electron microscopy. The goal of the PhD is to elucidate:
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How does the kinetics of the self-assembly sculpt the complex spatial organization of the micro-structure for composite gels ?
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What are the microscopic mechanisms governing their toughening under mechanical loads ?
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What are the impacts of the NPs spatio-temporal organization and polymers-nanoparticle bond dynamics on their self-healing abilities ?
Location and practical aspects
The successful candidate will benefit from the international outreach of the University of Grenoble Alpes. The core of the thesis will be on computational modeling at laboratory Soils, Solids, Structures, Risks in the “CoMHet” team gathering renowned experts in the physics and mechanics of divided media, soft architectured and bio-mimetic materials. In parallel, the PhD student will also contribute to experiments at CERMAV, a fundamental research CNRS laboratory which has internationally recognized expertise in the controlled chemical modification of natural carbohydrate polymers, their assembly in functional materials and their physico-chemical characterizations.
– Requests for thesis grant funding submitted and expertise in progress.
– Starting date: November 2021 for a period of 3 years.
Profile and required skills
Candidates with academic backgrounds in statistical physics, soft matter or physico-chemistry are expected. Specific skills in numerical modeling will be strongly appreciated. Additional knowledge in polymer physics and colloidal materials will be interestingly examined.
Interested candidates should send their CV, a cover letter and official transcripts of the last two years before 2021, May the 21st to Mehdi Bouzid, mehdi.bouzid@3sr-grenoble.fr.
PhD position : Contaminants transport through (nano) cellulose fibers networks: 3D characterization and mult-scale modelling
Localisation
The end of single plastic packaging is scheduled in France (~2030) and in Europe (~2040). Cellulosic materials such as paper and cardboard are today the only viable bio-sourced alternative, biodegradable and already 70% recycled, which can reach a mass market. Paper is a multiporous material with a large surface area accessible to contaminants. The transport of contaminants via the gas phase or cycles of (ad)sorption/desorption between the different components (shipping boxes, paper, and board), between the fibers and finally between the food particles (powder, grains, flake) is supposed to be the critical factor in food packaging. The roles of the connectivity of voids, micro-, and macro-pores, and the effects of the entanglement of fibers, specific surface area, surface composition, and relative humidity are poorly understood.
The aim of this PhD work is i) to perform an experimental characterization of the organization and morphologies of the fibrous network at microscopic and nanoscopic scales (from hundreds μm down to
20 nanometers) using X-ray Tomography. New materials with MFC based functional barrier will combine 150 to 400 μm thick paper with a 30 μm thick MFC (cellulose microfibres) layer. A stepwise procedure will be applied according to the size of the considered fibers in each layer and at their common interface. and ii) to reconstruct the 3D numerical models of such networks and fibers. These 3D models will be then use to investigate numerically contaminants transport through the (nano) cellulose fibers networks. The results of such multi-scale modelling will be compared to experimental data.
General information:
- Workplace: Laboratoire 3SR, Grenoble, France. This work will done in collaboration with the CTP (Centre Technique du Papier) in Grenoble.
- Contract from ANR FoodSafeBioPack
- Expected date of employment: 1st October 2021
- Deadline for application: 1st May 2021
- Growth monthly salary is about 2780€.
- Desired level of education: Master degree or equivalent
- Contact: Christian.geindreau@3sr-grenoble.fr, sabine.rollandduroscoat@3sr-grenoble.fr
Skills
This PhD position requires strong skills in material science and numerical modeling. An experience in
image processing and X-ray tomography is a plus.
Interested in this position? please send a CV, a motivation letter and your transcripts to the contact persons