Thuy Nguyen, lecturer-researcher in mechanics and materials at the ESILV engineering school and associate researcher at SPEC / CEA Saclay, is the co-head of the MISTIC (new Materials, Intelligent Systems and Innovative Companies) research axis of the DVRC. She holds a Magistère PHYTEM from ENS Cachan and a Ph.D. in Physics from the Paris-Saclay University. Her current research interests focus on new tough lightweight metamaterials, encompassing the entire process from design, optimisation, numerical simulation to additive manufacturing and experimental characterization.
Yosra Rmili; Tien Tung Ngo; El-Hadj Kadri; Ammar Yahia; Masoud Hosseinpoor; Thuy Nguyen
New empirical test method to assess Reynolds dilatancy of concrete under free-surface flow Journal Article
In: Construction And Building Materials, vol. 411, pp. 134762, 2024.
@article{rmili_2653,
title = {New empirical test method to assess Reynolds dilatancy of concrete under free-surface flow},
author = {Yosra Rmili and Tien Tung Ngo and El-Hadj Kadri and Ammar Yahia and Masoud Hosseinpoor and Thuy Nguyen},
url = {https://www.sciencedirect.com/science/article/pii/S0950061823044835?via%3Dihub},
year = {2024},
date = {2024-01-01},
journal = {Construction And Building Materials},
volume = {411},
pages = {134762},
abstract = {In this study, a new test method was proposed to evaluate the shear-induced volumetric changes, namely Reynolds dilatancy (RD), of sixteen conventional vibrated concrete (CVC) mixtures under free-surface flow. The RD measurements were carried out using a rheometer set-up and different vane-blade types rotating at different speeds. According to the experimental results, the RD values were found in good agreement with the workability of the investigated mixtures. Moreover, the RD values were well correlated with the coupled effect of the relative solid packing fraction of coarse aggregate (?/?max) and viscoplastic properties of the investigated CVC mixtures. Furthermore, a strong correlation was established between the rheological properties of the lubrication layer, RD values, and the ?/?max of coarse aggregate.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Laura Schittecatte; Valérie Geertsen; Daniel Bonamy; Thuy Nguyen; Patrick Guenoun
From resin formulation and process parameters to the final mechanical properties of 3D printed acrylate materials Journal Article
In: Mrs Communications, vol. 13, pp. 357-377, 2023.
@article{schittecatte_2327,
title = {From resin formulation and process parameters to the final mechanical properties of 3D printed acrylate materials},
author = {Laura Schittecatte and Valérie Geertsen and Daniel Bonamy and Thuy Nguyen and Patrick Guenoun},
url = {https://link.springer.com/article/10.1557/s43579-023-00352-3},
year = {2023},
date = {2023-04-01},
journal = {Mrs Communications},
volume = {13},
pages = {357-377},
abstract = {Photopolymerizable resins are increasingly used to generate complex 3D printed parts through stereo lithography, digital light processing (DLP) and
liquid crystal display (LCD) 3D printing. Many challenges relating to the resin chemistry and printing parameters still exist and must be addressed in order to entirely control the properties of parts after printing. This work reviews the current knowledge and describes the potential of DLP/LCD methods for printed acrylate resins, as well as the steps necessary to achieve a better control over the mechanical properties of printed materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Antoine Montiel; Thuy Nguyen; Cindy Rountree; Valérie Geertsen; Patrick Guenoun; Daniel Bonamy
Effect of architecture disorder on the elastic response of two-dimensional lattice materials Journal Article
In: Physical Review E, vol. 106, no. 1, pp. 015004, 2022.
@article{montiel_1922,
title = {Effect of architecture disorder on the elastic response of two-dimensional lattice materials},
author = {Antoine Montiel and Thuy Nguyen and Cindy Rountree and Valérie Geertsen and Patrick Guenoun and Daniel Bonamy},
url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.106.015004?ft=1},
year = {2022},
date = {2022-07-01},
journal = {Physical Review E},
volume = {106},
number = {1},
pages = {015004},
abstract = {We examine how disordering joint position influences the linear elastic behavior of lattice materials via numerical simulations in two-dimensional beam networks. Three distinct initial crystalline geometries are selected as representative of mechanically isotropic materials with low connectivity, mechanically isotropic materials with high connectivity, and mechanically anisotropic materials with intermediate connectivity. Introducing disorder generates spatial fluctuations in the elasticity tensor at the local (joint) scale. Proper coarse-graining reveals a well-defined continuum-level scale elasticity tensor. Increasing disorder aids in making initially anisotropic materials more isotropic. The disorder impact on the material stiffness depends on the lattice connectivity: Increasing the disorder softens lattices with high connectivity and stiffens those with low connectivity, without modifying the scaling between elastic modulus and density (linear scaling for high connectivity and cubic scaling for low connectivity). Introducing disorder in lattices with intermediate fixed connectivity reveals both scaling: the linear scaling occurs for low density, the cubic one at high density, and the crossover density increases with disorder. Contrary to classical formulations, this work demonstrates that connectivity is not the sole parameter governing elastic modulus scaling. It offers a promising route to access novel mechanical properties in lattice materials via disordering the architectures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thuy Nguyen; Daniel Bonamy
Role of the Crystal Lattice Structure in Predicting Fracture Toughness Journal Article
In: Physical Review Letters, vol. 123, no. 20, pp. 205503, 2019.
@article{nguyen_1496,
title = {Role of the Crystal Lattice Structure in Predicting Fracture Toughness},
author = {Thuy Nguyen and Daniel Bonamy},
url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.205503},
year = {2019},
date = {2019-11-01},
journal = {Physical Review Letters},
volume = {123},
number = {20},
pages = {205503},
abstract = {We examine the atomistic scale dependence of a material's resistance to failure by numerical simulations and analytical analysis in electrical analogs of brittle crystals. We show that fracture toughness depends on the lattice geometry in a way incompatible with Griffith's relationship between fracture and free surface energy. Its value finds its origin in the matching between the continuum displacement field at the engineering scale, and the discrete nature of solids at the atomic scale. The generic asymptotic form taken by this field near the crack tip provides a solution for this matching, and subsequently a way to predict toughness from the atomistic parameters with application to graphene},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Viet Hung Nguyen; Thuy Nguyen
Approximating the asymmetric profitable tour Journal Article
In: International Journal of Mathematics in Operational Research, vol. 4, pp. 294-301, 2012.
@article{nguyen_2747,
title = {Approximating the asymmetric profitable tour},
author = {Viet Hung Nguyen and Thuy Nguyen},
url = {https://www.sciencedirect.com/science/article/pii/S1571065310001162},
year = {2012},
date = {2012-04-01},
journal = {International Journal of Mathematics in Operational Research},
volume = {4},
pages = {294-301},
abstract = {We study the version of the asymmetric prize collecting travelling salesman problem, where the objective is to find a directed tour that visits a subset of vertices such that the length of the tour plus the sum of penalties associated with vertices not in the tour is as small as possible. In Dell'Amico et al. (1995), the authors defined it as the Profitable Tour Problem (PTP). We present an (1 + ?log( n )?)-approximation algorithm for the asymmetric PTP with n is the vertex number. The algorithm that is based on Frieze et al.'s heuristic for the asymmetric travelling salesman problem as well as a method to round fractional solutions of a linear programming relaxation to integers (feasible solution for the original problem), represents a directed version of the Bienstock et al.'s (1993) algorithm for the symmetric PTP.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thuy Nguyen; Daniel Bonamy; Laurent Pham Van; Jacques Cousty; Luc Barbier
In: Epl, vol. 89, pp. 60005, 2010.
@article{nguyen_2745,
title = {Scaling and universality in the kinetic smoothening of interfaces: Application to the analysis of the relaxation of rough vicinal steps of an oxide surface},
author = {Thuy Nguyen and Daniel Bonamy and Laurent Pham Van and Jacques Cousty and Luc Barbier},
url = {https://iopscience.iop.org/article/10.1209/0295-5075/89/60005/meta},
year = {2010},
date = {2010-04-01},
journal = {Epl},
volume = {89},
pages = {60005},
abstract = {Relaxation of initially out-of-equilibrium rough interfaces in the presence of thermal noise is investigated using Langevin formalism. During thermal equilibration towards the well-known roughening regime, three scaling regimes observed over three successive ranges of length-scales are evidenced: thermal roughening (late stage) at small scales, transient smoothening at intermediate scales and remnant of the initial conditions at large scales. A generalization of the Family-Vicsek scaling is found for the smoothening regime. This approach allows interpreting a series of AFM images of sapphire surfaces showing the thermal evolution of initially rough step edges.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thuy Nguyen; Daniel Bonamy; Laurent Pham Van; Luc Barbier; Jacques Cousty
Coarsening of two-dimensional Al2O3 islands on vicinal (1, -1, 0, 2) sapphire surfaces during annealing in air Journal Article
In: Surface Science, vol. 602, no. 21, pp. 3232-3238, 2008.
@article{nguyen_2746,
title = {Coarsening of two-dimensional Al2O3 islands on vicinal (1, -1, 0, 2) sapphire surfaces during annealing in air},
author = {Thuy Nguyen and Daniel Bonamy and Laurent Pham Van and Luc Barbier and Jacques Cousty},
url = {https://www.sciencedirect.com/science/article/pii/S0039602808005645},
year = {2008},
date = {2008-11-01},
journal = {Surface Science},
volume = {602},
number = {21},
pages = {3232-3238},
abstract = {The evolution of two-dimensional (2D) islands which result from a chemo-mechanical polishing of vicinal (1, ?1, 0, 2) sapphire surfaces was explored by atomic force microscopy (AFM) after annealing in air. The evolution of the surface morphology is followed after isothermal annealing (1173 K) for duration varying from 1 h to 53 h and isochronal annealing at temperatures between 1023 K < T < 1253 K. Statistical analysis of the AFM images gives evidence that an anisotropic Ostwald ripening governs the evolution of the 2D island distribution. The activation energy for mass transport on the terrace is found to be 1.3 ± 0.1 eV.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Laura Schittecatte; Valérie Geertsen; Daniel Bonamy; Patrick Guenoun; Thuy Nguyen
19th European Mechanic of Materials Conference, Madrid, Spain, 2024.
@conference{schittecatte_3098,
title = {3D printed polymers by photopolymerization: link between resin chemistry, printing parameters and mechanical properties},
author = {Laura Schittecatte and Valérie Geertsen and Daniel Bonamy and Patrick Guenoun and Thuy Nguyen},
editor = {European Mechanics Society, Euromech},
url = {https://easychair.org/smart-program/EMMC19/2024-05-29.html#session:82275},
year = {2024},
date = {2024-05-01},
booktitle = {19th European Mechanic of Materials Conference},
address = {Madrid, Spain},
abstract = {3D printed polymer materials present a growing interest in a number of fields including aerospace, energy, construction industries, as well as bioengineering applications [1]-[3]. While conventional molded or extruded polymer materials are well known and characterized via standardized procedures, this is not the case for 3D printed polymers. More precisely, it is of prime importance to better understand the influence of the 3D photopolymerization process and resin chemistry on the final mechanical properties of the object [4]. In our work, we formulated in-house acrylate resins with controlled resin chemistry. The resin physico-chemical properties and their printability were fully characterized. In particular, we investigated the influence of the nature of the acrylate monomer on the resin properties. Besides, after successful printing, the resin mechanical properties were investigated via Dynamic Mechanical Analysis (DMA) in flexion to determine the elastic modulus of the final materials. The results were compared to a molded analog acrylic polymethyl methacrylate (PMMA) and to commercial resins. We observed that by tuning the resin formulation and optimizing the printing process, it is possible to achieve PMMA-like stiffnesses with 3D printed pure acrylate resins. A statistical analysis was also performed, revealing a greater dispersion of the results in terms of reproducibility for 3D printed materials (both commercial and formulated resins) with respect to that in molded PMMA. However, our homemade resins have a lower dispersion than commercial resins, which underlines the importance of controlling both resin chemistry and printing parameters.},
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pubstate = {online},
tppubtype = {conference}
}
Thuy Nguyen
Mechanical behaviour of bio-inspired beam lattice metamaterials Conference
Colloque national annuel MecaMat, Aussois, France, 2023.
@conference{nguyen_2184,
title = {Mechanical behaviour of bio-inspired beam lattice metamaterials},
author = {Thuy Nguyen},
editor = {MecaMat},
url = {https://aussois2023.sciencesconf.org/},
year = {2023},
date = {2023-01-01},
booktitle = {Colloque national annuel MecaMat},
address = {Aussois, France},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Thuy Nguyen; Daniel Bonamy
Effect of atomic-scale solid discreetness in brittle fracture problem Conference
11th European Solid Mechanics Conference, Galway, Ireland, 2022.
@conference{nguyen_1923,
title = {Effect of atomic-scale solid discreetness in brittle fracture problem},
author = {Thuy Nguyen and Daniel Bonamy},
url = {https://www.esmc2022.org/},
year = {2022},
date = {2022-07-01},
booktitle = {11th European Solid Mechanics Conference},
address = {Galway, Ireland},
abstract = {Material's resistance-to-failure is quantified by two dependent material constants (one is proportional to the square of the other): fracture energy and fracture toughness. Predicting their values from the solid structure at the atomistic scale remains insolved, even in the simplest situation of an ideal brittle fracture. By examining numerically crack growth in electrical analogues of brittle crystals with modulated geometries, we shed a new light on this question. We find that the value of fracture energy cannot be deduced from Griffith's free surface energy, as is generally believed [1]. Rather, it finds its origin in the matching between the continuum-level scale displacement field of solid mechanics and the discrete nature of solids at the atomic scale. By making use of the generic asymptotic form, referred to as Williams's series expansion [2], taken by the displacement field near the crack tip, we find an analytical solution for this matching, and subsequently a way to predict quantitativly fracture toughness from the atomistic parameters [3]. We will discuss how to extend the analysis to genuine elastic (plane stress) crack problems and predict fracture toughness in 2D and 3D materials. This work sheds new perspectives on how resistance-to-faillure is selected; and hence, how it can be improved. As such, it may catalyze novel research toward new architectured materials of superior strcutural performance via microstructure patterning : tougher, more durable, lighter and/or combining other functionalities.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Antoine Montiel; Paul Sargueil; Thuy Nguyen; Cindy Rountree; Valérie Geertsen; Patrick Guenoun; Daniel Bonamy
Mechanical & fracture behaviour of microlattice metamaterial with disordered architecture Conference
Mécanique des Matériaux Architecturés, MacaMat Aussois, France, 2022.
@conference{montiel_1775,
title = {Mechanical & fracture behaviour of microlattice metamaterial with disordered architecture},
author = {Antoine Montiel and Paul Sargueil and Thuy Nguyen and Cindy Rountree and Valérie Geertsen and Patrick Guenoun and Daniel Bonamy},
url = {https://aussois2022.sciencesconf.org/},
year = {2022},
date = {2022-01-01},
booktitle = {Mécanique des Matériaux Architecturés},
address = {Aussois, France},
organization = {MacaMat},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Antoine Montiel; Thuy Nguyen; Valérie Geertsen; Cindy Rountree; Patrick Guenoun; Daniel Bonamy
ELASTIC BEHAVIOUR OF 2D-MICROBEAM-BASED LATTICE METAMATERIALS IN PRESENCE OF MODULATED ARCHITECTURE DISORDER Proceedings Article
In: International Conference of the Theoretical and Applied Mechanics, The International Union of Theoretical and Applied Mechanics Daegue, Korea, 2024.
@inproceedings{montiel_3094,
title = {ELASTIC BEHAVIOUR OF 2D-MICROBEAM-BASED LATTICE METAMATERIALS IN PRESENCE OF MODULATED ARCHITECTURE DISORDER},
author = {Antoine Montiel and Thuy Nguyen and Valérie Geertsen and Cindy Rountree and Patrick Guenoun and Daniel Bonamy},
url = {https://www.ictam2024.org/index.php?GP=int/int05},
year = {2024},
date = {2024-08-01},
booktitle = {International Conference of the Theoretical and Applied Mechanics},
address = {Daegue, Korea},
organization = {The International Union of Theoretical and Applied Mechanics},
abstract = {We explore the impact of architectural disorder on the linear elastic behavior of lattice materials through 2D beam network numerical simulations. Different initially periodic geometries are first selected as representative of mechanically isotropic or anisotropic structures and low, intermediate, and large connectivity. The introduction of disorder induces spatial fluctuations in the local elasticity tensor at the local scale. Through proper coarse-graining, a well-defined continuum-level scale elasticity tensor is revealed. Increased disorder contributes to rendering initially anisotropic materials more isotropic. The impact of disorder on material stiffness depends on lattice connectivity: disorder softens lattices with high connectivity and stiffens those with low connectivity, while maintaining the linear scaling of elastic modulus with density for high connectivity and cubic scaling for low connectivity. Disorder introduced in lattices with intermediate fixed connectivity exhibits both scaling: linear scaling at low density and cubic scaling at high density, with the crossover density increasing with disorder. Contrary to traditional formulations, this study demonstrates that connectivity is not the sole parameter governing elastic modulus scaling. It opens a promising route to explore novel mechanical properties in lattice materials by introducing disorder into the architectures.},
keywords = {},
pubstate = {online},
tppubtype = {inproceedings}
}
Thuy Nguyen; Daniel Bonamy
Contribution to Griffith theory of fracture for predicting fracture toughness Proceedings Article
In: The 14th International Conference of Computational, Ho Chi Minh, Vietnam, 2023.
@inproceedings{nguyen_2546,
title = {Contribution to Griffith theory of fracture for predicting fracture toughness},
author = {Thuy Nguyen and Daniel Bonamy},
url = {https://www.sci-en-tech.com/ICCM/index.php/ICCM2023/index/about},
year = {2023},
date = {2023-08-01},
booktitle = {The 14th International Conference of Computational},
address = {Ho Chi Minh, Vietnam},
abstract = {Fracture toughness and fracture energy are two key, interrelated, parameters characterising the
material resistance-to-failure. Predicting these values from the solid structure at the atomistic
scale remains elusive, even in the simplest situations of ideal brittle fracture. By using numerical
simulations on scalar lattice models of fracture, we demonstrate that fracture toughness cannot
be deduced from Griffith's specific surface energy, as is generally believed. Rather, it finds its
origin in the matching between the continuum displacement field at the engineering scale and the
discrete lattice of solids at the atomic scale. The generic asymptotic form taken by this field near
crack tip provides a solution for this matching, and subsequently a way to predict toughness
from the atomistic parameters. This method is extended to true vectorial elasticity and is used
to revisit the fracture toughness/fracture energy values observed in bidimensional crystalline
materials like graphene},
keywords = {},
pubstate = {online},
tppubtype = {inproceedings}
}
Thuy Nguyen; Daniel Bonamy
Lattice trapping and fracture toughness selection in britttle crystals Proceedings Article
In: 25th International Congress of Theoretical and Applied Mechanics, Milano, Italy, 2021.
@inproceedings{nguyen_1272,
title = {Lattice trapping and fracture toughness selection in britttle crystals},
author = {Thuy Nguyen and Daniel Bonamy},
url = {https://www.ictam2020.org/},
year = {2021},
date = {2021-08-01},
booktitle = {25th International Congress of Theoretical and Applied Mechanics},
address = {Milano, Italy},
keywords = {},
pubstate = {published},
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Antoine Montiel; Thuy Nguyen; M Perchelet; Valérie Geertsen; Cindy Rountree; Patrick Guenoun; Daniel Bonamy
Mechanical and fracture behaviour of microlattice-based metamaterial with disordered architecture Proceedings Article
In: 25th International Congress of Theoretical and Applied Mechanics, Milan, Italy, 2021.
@inproceedings{montiel_1498,
title = {Mechanical and fracture behaviour of microlattice-based metamaterial with disordered architecture},
author = {Antoine Montiel and Thuy Nguyen and M Perchelet and Valérie Geertsen and Cindy Rountree and Patrick Guenoun and Daniel Bonamy},
url = {https://www.ictam2020.org/},
year = {2021},
date = {2021-08-01},
booktitle = {25th International Congress of Theoretical and Applied Mechanics},
address = {Milan, Italy},
abstract = {Microlattice based metamaterials made of periodically arranged hollow microtubes appear as highly promising materials; they
both combine ultra-low density and sufficient stiffness and mechanical strength to envisage their use as structure material, in the aeronautical
industry for instance. Still, until now, most studies have considered periodically ordered architectures. Here, we explored amorphous
architectures and analysed how the disorder amount plays on the mechanical and failure properties. The presented study relies on both
numerical simulations using Timoshenko beam model and experiments performed on 3D-printed samples, the architecture of which mimics
that of the simulated samples},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Daniel Bonamy; Thuy Nguyen
Breaking news : les solides fragiles le sont moins que prévu ! Miscellaneous
CEA, 2019.
@misc{bonamy_1497,
title = {Breaking news : les solides fragiles le sont moins que prévu !},
author = {Daniel Bonamy and Thuy Nguyen},
url = {http://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast.php?t=fait_marquant&id_ast=3180},
year = {2019},
date = {2019-12-01},
howpublished = {CEA},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Antoine Montiel; Daniel Bonamy; Cindy Rountree; Paul Sargueil; Valérie Geertsen; Patrick Guenoun; Thuy Nguyen
Method for producing an amorphous architecture of the microlattice type formed of micro-beams connected together by nodes Technical Report
Brevet WIPO no. 2023/174953, 2023.
@techreport{montiel_2748,
title = {Method for producing an amorphous architecture of the microlattice type formed of micro-beams connected together by nodes},
author = {Antoine Montiel and Daniel Bonamy and Cindy Rountree and Paul Sargueil and Valérie Geertsen and Patrick Guenoun and Thuy Nguyen},
url = {https://www.onscope.com/ipowner/fr/ip/ptwo/EP2023056515.html},
year = {2023},
date = {2023-09-01},
number = {2023/174953},
institution = {Brevet WIPO},
note = {The invention relates to a method for producing an amorphous three-dimensional architecture of the micro-lattice type formed of micro-beams connected together by nodes, which comprises: A) performing (100) a computer-implemented design step consisting, on the basis of a three-dimensional random arrangement (INIT) of non-deformable beads, in: a) producing (101) a three-dimensional random compact stack of said beads; b) for each bead, determining (102) the coordinates of the centre of the bead which correspond to those of a node; c) performing (103) a triangulation with said nodes, each triangle thus being defined with the nodes closest to one another, then associating two nodes connected by one side of a triangle to a micro-beam in order to define the micro-lattice; d) selecting (104) a sub-domain of the micro-lattice obtained in step c), not comprising the nodes located at the edge of the micro-lattice in order to define said amorphous three-dimensional architecture, the design step involving an average connectivity of the nodes greater than or equal to twelve, the design step providing for defining a shape and associated transverse dimensions for each micro-beam; and B) producing (200) the architecture designed in step A).},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
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