Publications

2019

• Extension of the lubrication theory for arbitrary wall shape: An asymptotic analysis
  
  • Hinojosa Rogers Bill Cordova
  • Pham Kim
  • Rouby Corinne
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2019, 347 (5), pp.389-396. (10.1016/j.crme.2019.03.016)
  DOI : 10.1016/j.crme.2019.03.016
• Biomechanical properties of the human mandibular cadaveric bone related to ramus sagittal osteotomy
  
  • Rougier G.
  • Kogane N.
  • Dallard J.
  • Mangione F.
  • Slimani L.
  • Salmon B.
  • Thurieau N.
  • Cherfa L.
  • Kadlub N.
  • Boisson J.
  • Szmytka Fabien
  Computer Methods in Biomechanics and Biomedical Engineering, Taylor & Francis, 2019, 22 (sup1), pp.S96-S98. (10.1080/10255842.2020.1713494)
  DOI : 10.1080/10255842.2020.1713494
• A numerical model for multiphase liquid–vapor–gas flows with interfaces and cavitation
  
  • Pelanti Marica
  • Shyue Keh-Ming
  International Journal of Multiphase Flow, Elsevier, 2019, 113, pp.208 - 230. (10.1016/j.ijmultiphaseflow.2019.01.010)
  DOI : 10.1016/j.ijmultiphaseflow.2019.01.010
• A Hybrid High-Order method for incremental associative plasticity with small deformations
  
  • Abbas Mickaël
  • Ern Alexandre
  • Pignet Nicolas
  Computer Methods in Applied Mechanics and Engineering, Elsevier, 2019, 346, pp.891-912. We devise and evaluate numerically a Hybrid High-Order (HHO) method for incremental associative plasticity with small deformations. The HHO method uses as discrete unknowns piecewise polynomials of order k ≥ 1 on the mesh skeleton, together with cell-based poly-nomials that can be eliminated locally by static condensation. The HHO method supports polyhedral meshes with non-matching interfaces, is free of volumetric-locking and the integration of the behavior law is performed only at cell-based quadrature nodes. Moreover, the principle of virtual work is satisfied locally with equilibrated tractions. Various two-and three-dimensional test cases from the literature are presented including comparison against known solutions and against results obtained with an industrial software using conforming and mixed finite elements. (10.1016/j.cma.2018.08.037)
  DOI : 10.1016/j.cma.2018.08.037
• Enhanced resonance of sparse arrays of Helmholtz resonators—Application to perfect absorption
  
  • Maurel Agnès
  • Mercier Jean-François
  • Pham Trung Kien
  • Marigo J.-J
  • Ourir Abdelwaheb
  Journal of the Acoustical Society of America, Acoustical Society of America, 2019, 145 (4), pp.2552-2560. We inspect the influence of the spacing on the resonance of a periodic arrangement of Helmholtz resonators. An effective problem is used which captures accurately the properties of the resonant array within a large range of frequency, and whose simplified version leaves us with an impedance condition. It is shown that the strength of the resonance is enhanced when the array becomes sparser. This degree of freedom on the radiative damping is of particular interest since it does not affect the resonance frequency nor the damping due to losses within each resonator; besides, it does not affect the total thickness of the array. We show that it can be used for the design of a perfect absorbing walls. (10.1121/1.5098948)
  DOI : 10.1121/1.5098948
• Dynamiques transitoires de sillage dans le pinball fluidique
  
  • Deng Nan
  • Pastur Luc
  • Noack Bernd R.
  • Cornejo-Maceda Guy
  • Lusseyran François
  • Loiseau Jean-Christophe
  • Morzyński Marek
  , 2019. Nous nous intéressonsà la dynamique transitoire d'une configuration fluide formée de trois cylindres fixes distribués sur un triangleéquilatéral enécoulement transverse (pinball fluidique), pour différentes valeurs du nombre de Reynolds sur la route vers le chaos. Nousétudions plus particulièrement l'action des degrés de liberté elémentaires du système dynamique sous-jacent sur les coefficients de trainée et de portance de l'écoulement fluide.
• Nucleation of supercooled Co melts under a high magnetic field
  
  • Wang Jun
  • He Yixuan
  • Li Jinshan
  • Li Chao
  • Kou Hongchao
  • Zhang Pingxiang
  • Beaugnon Eric
  Materials Chemistry and Physics, Elsevier, 2019, 225, pp.133-136. (10.1016/j.matchemphys.2018.12.070)
  DOI : 10.1016/j.matchemphys.2018.12.070
• Extended source models for wind turbine noise propagation
  
  • Cotté Benjamin
  Journal of the Acoustical Society of America, Acoustical Society of America, 2019, 145 (3), pp.1363-1371. (10.1121/1.5093307)
  DOI : 10.1121/1.5093307
• Nonlinear energy transfer to improve the acoustic black hole effect
  
  • Li Haiqin
  • Denis Vivien
  • Pelat Adrien
  • Gautier François
  • Touzé Cyril
  , 2019. Acoustic Black Hole effect (ABH) describes a passive vibration mitigation technique used to damp out the flexural vibrations of thin structures such as beams. It relies on a wedge profile where the thickness is gradually decreasing, so that wave velocities slows down, potentially decaying to zero without reflection. The device generally shows very interesting damping properties in the mid and high-frequency range, however its efficiency in the low-frequency range still remains limited. In this contribution, the inclusion of a nonlinearity as a way to improve the low-frequency performance of an ABH is investigated. Indeed, the nonlinearity may be used as a vector to transfer energy from the low to the high frequency range, where the damping properties are much more significant. Two different mechanisms are tested, based respectively on geometric and contact nonlinearity.
• Nonlinear vibrations of thin plates with variable thickness: Application to sound synthesis of cymbals
  
  • Nguyen Quoc Bao
  • Touzé Cyril
  Journal of the Acoustical Society of America, Acoustical Society of America, 2019, 145 (2), pp.977-988. Geometrically nonlinear vibrations of thin plates and shells with variable thickness are investigated numerically with the purpose of synthesizing the sound of cymbals. In cymbal making, taper refers to the gradual change in thickness from the centre to the rim, and is known to be a key feature that determines the tone of the instrument. It is generally used in conjunction with shape variations in order to enable the cymbal to play a bell-like sound when hit near its centre, or a crash sound when struck close to the edge. The von Kármán equations for thin plates with thickness and shape variations are derived, and a numerical method combining a Rayleigh-Ritz approach together with a Störmer-Verlet scheme for advancing the problem in time, is detailed. One main advantage of the method is its ability to implement easily any frequency-dependent loss mechanism which is a key property for sound synthesis. Also, the accuracy of the computation of the nonlinear restoring force is especially preserved. The method is employed to synthesize the sounds of cymbal-like instruments. The impact of taper is addressed and the relative effects of both thickness and shape variations, are contrasted. (10.1121/1.5091013)
  DOI : 10.1121/1.5091013
• Multi-model coupling for fluid structure interaction
  
  • Fernier Alexandre
  , 2019. In nuclear industry, simulating accidental transient sequences at full reactor scale is becoming an increasingly important feature of the safety demonstration towards national agencies. It thus allows limiting the number of complex and costly experiments, while simplifying and accelerating the evaluation of mitigation strategies. However, the implemented numerical models are inevitably heavy to build and maintain, with a global modelling scale making it difficult to account for local geometric details yet able to significantly influence the physical solution. To provide an answer to these problems, this PhD work is dedicated to multi-model approaches designed to integrate such details into bigger models with no modification at the global level (techniques often designated as numerical zoom techniques). Some methods are proposed for both structures and fluids, with special care given to the accuracy and stability of the coupled multi-scale solution compared to a single-scale reference solution. This work handles two very specific topics, namely its compatibility with numerical features imposed by fast transient dynamics with explicit time integration, and the general objective of simultaneously dealing with superimposed models and fluid-structure interaction. (10.70675/66cde02az90e2z4ba4z9ce2z6119a33becd2)
  DOI : 10.70675/66cde02az90e2z4ba4z9ce2z6119a33becd2
• Nonlinear magnetic vibration absorber for passive control of a multi-storey structure
  
  • Lo Feudo Stefania
  • Touzé Cyril
  • Boisson Jean
  • Cumunel Gwendal
  Journal of Sound and Vibration, Elsevier, 2019, 438, pp.33-353. A nonlinear magnetic vibration absorber is presented and used to control vibration of a three-storey structure. A distinctive feature of the absorber concerns its versatility for tuning the linear and nonlinear stiffness coefficients, depending on simple geometric design parameters such as the distance between fixed magnets and the moving one. In particular, the absorber can be set either as a nonlinear tuned vibration absorber, a nonlinear energy sink, or a bistable tuned vibration absorber, according to whether the linear stiffness term is positive, vanishing, or negative. The response of the primary structure and the vibration mitigation are investigated in the cases of impulsive shock, free vibration with imposed initial displacement, and single frequency excitation. Significant reductions of the primary structure vibrations are obtained for the three cases investigated, showing the ability of using a vibration absorber only relying on magnetic forces for passive control. The detailed comparisons of the absorbers performance show that, in this case study, no general guidelines can be easily deduced for selecting one of the three tunings for a nonlinear absorber. Depending on the excitation, the vibratory levels, and the frequency content of the excitation, the three configurations show advantages and drawbacks that are discussed. (10.1016/j.jsv.2018.09.007)
  DOI : 10.1016/j.jsv.2018.09.007
• Artificial intelligence control applied to drag reduction of the fluidic pinball
  
  • Cornejo Maceda Guy y
  • Noack Bernd R
  • Lusseyran François
  • Deng Nan
  • Pastur Luc
  • Morzynski Marek
  PAMM, Wiley-VCH Verlag, 2019, 19 (1), pp.e201900268. The aim of our work is to advance a self-learning, model-free control method to tame complex nonlinear flows-building on the pioneering work of Dracopoulous [1]. The cornerstone is the formulation of the control problem as a function optimization problem. The control law is derived by solving a nonsmooth optimization problem thanks to an artificial intelligence technique, genetic programming (GP). Metaparameters optimization of the algorithm and complexity penalization have been our main contribution and have been tested on a cluster of three equidistant cylinders immersed in a incoming flow, the fluidic pinball. The means of control is the independent rotation of the cylinders. GP derived a control law associated to each cylinder in order to minimize the net drag power and managed to outperform past open-loop studies with a 46.0 % net drag power reduction by combining two strategies from literature. This success of MIMO control including sensor history is promising for exploring even more complex dynamics. (10.1002/pamm.201900268)
  DOI : 10.1002/pamm.201900268
• Galerkin-free model reduction for fluid-structure interaction using proper orthogonal decomposition
  
  • Shinde Vilas
  • Longatte Elisabeth
  • Baj Franck
  • Hoarau Yannick
  • Braza Marianna
  Journal of Computational Physics, Elsevier, 2019, 396, pp.579-595. A Galerkin-free model reduction approach for fluid-structure interaction (FSI) is presented in this article. The reduced order model (ROM) is based on proper orthogonal decomposition (POD), where a reduced basis is formed using energy dominant POD modes. The reduced basis also consists of characteristics POD time modes that are derived from the POD time modes (coefficients) by using their periodicity. In addition to flow variables, the solution state vector comprises the mesh deformation, taking into account the structural deformation in FSI. A ROM solution is obtained by performing a linear interpolation of the reduced basis for changing operating/control parameters. The proposed Galerkin-free POD-ROM approach is demonstrated in terms of two test cases: a canonical case study of vortex-induced vibration (VIV) of a cylinder at Reynolds number Re = 100, where simulations are performed for various structural-to-fluid mass ratios; and a shock wave boundary layer induced panel flutter. For the second case, we use previously computed high-fidelity simulations, considering only the effect of panel thickness on the aeroelastic coupling between the flexible panel and shock wave boundary layer interaction (SWBLI); the inflow is at Mach 2 and Reynolds number based on panel length Rea = 50000. The presented Galerking-free ROM procedure is clean and robust for large mesh deformations, in addition to a significantly lower cost of computation compared to the FSI high-fidelity simulations. (10.1016/j.jcp.2019.06.073)
  DOI : 10.1016/j.jcp.2019.06.073
• A HOMOGENEOUS MODEL FOR COMPRESSIBLE THREE-PHASE FLOWS INVOLVING HEAT AND MASS TRANSFER.
  
  • Hurisse Olivier
  • Quibel Lucie
  ESAIM: Proceedings and Surveys, EDP Sciences, 2019. A homogeneous model is proposed in order to deal with the simulation of fast transient three-phase flows involving heat and mass transfer. The model accounts for the full thermodynam-ical disequilibrium between the three phases in terms of pressure, temperature and Gibbs enthalpy. The heat and mass transfer between the phases is modeled in agreement with the second law of ther-modynamics, which ensures a stable return to the thermodynamical equilibrium. The set of partial differential equations associated with this model is based on the Euler set of equations supplemented by a complex pressure law, and by six scalar equations that allow to account for the thermodynamical disequilibrium. It therefore inherits a simple wave structure and possesses important mathematical properties such as: hyperbolicity, unique shock definition through Rankine-Hugoniot relations, pos-itivity of the mixture fractions. Hence the computation of approximated solutions is possible using classical algorithms, which is illustrated by an example of simulation of a steam-explosion.
• Plastic zone evolution during fatigue crack growth: Digital image correlation coupled with finite elements method
  
  • Hosdez Jérôme
  • Langlois Mederic
  • Witz J-F
  • Limodin N.
  • Najjar D.
  • Charkaluk E.
  • Osmond P.
  • Forre A.
  • Szmytka F.
  International Journal of Solids and Structures, Elsevier, 2019, 171, pp.92-102. Nonlinearities effects at the crack tip, due to the elastic-plastic material behavior , impact the crack growth rate and path. This paper is devoted to the study of the plastic zone evolution in the crack tip region. The methodology relies on coupling an elastic-plastic Finite Elements Method (FEM) model and experimental displacements measured by Digital Image Correlation (DIC). These latter are introduced as Dirichlet boundary conditions in the finite elements analysis. The considered FEM domain is constant, i.e. the same mesh with a centered crack is moved to each new crack tip position deduced from DIC. The new boundary conditions are updated and the residual stresses and plastic strains of the former computation are interpolated and actualized on the mesh shifted to the new crack tip position in order to incorporate them in the numerical model. The coupling method allowed applying experimental boundary conditions in order to be as close as possible to real experimental conditions and to observe the plasticity evolution from small to large scale yielding conditions. A fatigue test was conducted to validate the proposed approach. The identification residues are proved to be lower than those obtained with an experimental displacements projection onto Williams' series basis, which is a method commonly used with DIC. The coupling results present an attractive similarity with Irwin's model regardless of the crack length. Thus, the definition of the mask needed for the displacements fields projection on Williams' model can be deduced with a reliable estimate of Irwin's plastic radius. (10.1016/j.ijsolstr.2019.04.032)
  DOI : 10.1016/j.ijsolstr.2019.04.032
• Fatigue crack growth under large scale yielding condition in a cast automotive aluminum alloy
  
  • Dézécot Sébastien
  • Rambaudon Matthieu
  • Köster Alain
  • Szmytka Fabien
  • Maurel Vincent
  • Buffière Jean-Yves
  Materials Science and Engineering: A, Elsevier, 2019, 743, pp.87-97. Low cycle fatigue crack growth tests have been performed at 250 • C in order to study fatigue crack growth under large scale yielding conditions in a material widely used at high temperature by the automotive industry for cylinder head applications. The studied material was a cast aluminum alloy AlSi7Cu3Mg (close to A319) produced by Lost Foam Casting. Two different microstructures were investigated: one containing large natural pores and another where pores have been removed by Hot Isostatic Pressing (HIP). Fatigue Crack Growth Rates (FCGR) have been measured by in situ surface optical microscopy for different loading conditions all inducing generalized plasticity and compared to assess the influence of pores on the FCGR. In situ observations coupled to post mortem analysis revealed strong crack interactions with both pores and large hard particles on specimen surfaces and in the bulk. FCGR ranging between 10 −6 and 10 −4 m/cycle appear to be mainly sensitive to applied strain amplitudes. Although pores promoted secondary crack initiations and crack coalescences, they seemed to have a limited effect on steady-state FCGR which has been analytically modeled using energy densities. (10.1016/j.msea.2018.03.008)
  DOI : 10.1016/j.msea.2018.03.008
• A micromechanical inspired model for the coupled to damage elasto-plastic behavior of geomaterials under compression
  
  • Marigo Jean-Jacques
  • Kazymyrenko Kyrylo
  Mechanics & Industry, EDP Sciences, 2019, 20 (1), pp.105. We propose an elasto-plastic model coupled with damage for the behavior of geomaterials in compression. The model is based on the properties, shown in [S. Andrieux, et al., Un modèle de matériau microfissuré pour les bétons et les roches, J. Mécanique Théorique Appliquée 5 (1986) 471?513], of microcracked materials when the microcracks are closed with a friction between their lips. That leads to a macroscopic model coupling damage and plasticity where the plasticity yield criterion is of the Drucker–Prager type with kinematical hardening. Adopting an associative flow rule for the plasticity and a standard energetic criterion for damage, the properties of such a model are illustrated in a triaxial test with a fixed confining pressure. (10.1051/meca/2018043)
  DOI : 10.1051/meca/2018043
• Experimental database of mixed-mode crack propagation tests performed on mortar specimens with a hexapod and full-field measurements. Part II: interactive loading
  
  • Carpiuc-Prisacari Andreea
  • Jailin Clément
  • Poncelet Martin
  • Kazymyrenko Kyrylo
  • Leclerc Hugo
  • Hild François
  Cement and Concrete Research, Elsevier, 2019, 125, pp.105867. This second paper presents a series of 4 crack propagation tests with the same experimental protocol as in a companion paper, but with some significant loading modifications. The first difference is that the loading is composed of in-plane rotation in addition to tension and shear translations. The second difference is that the loading is manually changed during the tests, depending on the crack tip location. This leads to tests with several bifurcations, and/or different loading ratios during the same test. One of them leads to mode I+II, and then mode I+III crack propagation. Some tests end with instabilities while others are controlled to be stable up to the complete failure of the specimen. In some cases, crack closure and friction between the crack faces occur. (10.1016/j.cemconres.2019.105867)
  DOI : 10.1016/j.cemconres.2019.105867
• Real-world outcomes with ranibizumab 0.5 mg in patients with visual impairment due to diabetic macular edema: 12-month results from the 36-month boreal-dme study
  
  • Massin P.
  • Creuzot-Garcher C.
  • Kodjikian L.
  • Girmens J.-F.
  • Delcourt C.
  • Fajnkuchen F.
  • Glacet-Bernard A.
  • Guillausseau P.-J.
  • Ponthieux A.
  • Blin P.
  • Grelaud A.
  Ophthalmic Research, 2019, 62 (2), pp.101-110. Purpose: To report the real-world effectiveness and safety of ranibizumab 0.5 mg in patients with visual impairment due to diabetic macular edema (DME). Methods: This is a French, 36-month, multicenter, observational cohort study. Between December 2013 and April 2015, ophthalmologists enrolled diabetic patients aged ≥18 years with DME-related visual impairment and for whom ranibizumab 0.5 mg was initiated. Here, we present the 12-month results from this cohort. The primary endpoint was the mean change in best-corrected visual acuity (BCVA); sample size calculations were based on RESTORE trial data (BCVA mean change = 6.8 letters, preci sion = 0.7 letters). Secondary endpoints included the change in central subfield thickness (CSFT), number of visits, number of injections received, and frequency of ocular and nonocular adverse events and serious adverse events. Results: Between December 2013 and April 2015, a total of 290 patients with DME were enrolled by 84 ophthalmologists; 12-month data are available for 242 patients (due to low recruitment rates, precision was recalculated for 242 evaluable patients: The precision was then of 1.0 letters). Mean age (± standard deviation) was 66.1 ± 11.0 years and 56.6% were male. The mean baseline BCVA and CSFT were 59.2 letters (95% confidence interval [CI] 57.3, 61.0) and 457 μm (95% CI: 438, 476), respectively. At month 12, the mean gain in BCVA from baseline was 7.4 letters (95% CI: 5.4, 9.4), with 36.8% of patients with BCVA > 70 letters versus 13.2% at baseline. Mean change in CSFT was-125 μm (95% CI:-146,-103). The mean number of ranibizumab injections was 5.1 ± 2.3 over an average of 10.4 ± 3.0 visits. No new safety findings were identified. Conclusions: The BOREAL study confirms the effectiveness and safety of ranibizumab for the treatment of DME-related visual impairment in routine clinical practice with fewer injections than reported in clinical trials. © 2019 S. Karger AG, Basel. (10.1159/000497406)
  DOI : 10.1159/000497406