Publications

2019

• Strain localization in ductile shear zones: This is a crystal plasticity's world, but it wouldn't be nothing without a micro-cracking or a sliding grain
  
  • Dimanov Alexandre
  • Bornert Michel
  • Raphanel Jean
  • Héripré Eva
  • Gharbi Hakim
  • Ababacar Gaye
  • Bourcier Mathieu
  • Ludwig Wolfgang
  • King Andrew
  , 2019. Strain localization in ductile shear zones: This is a crystal plasticity’s world, but it wouldn’t be nothing without a micro-cracking or a sliding grain Localization of ductile strain in rocks results in development of mylonites, which microstructures always display the signatures of several different micro-mechanisms operating at the grain and aggregate scales. Intense crystal plasticity and dynamic recrystallization coexist with micro-cracking, grain boundary migration and sliding, ductile cavitation and failure, diffusive and solution mass transfer along interfaces. Their chronology of activation, their interactions and their respective quantitative roles in the development of the localization process are still unclear. Therefore, a simple inference of the overall mylonitic rheology on the basis of one or another of the latter mechanisms seems illusory. In order to clarify the interplay of mechanisms at the onset of ductile deformation, we performed multi-scale full mechanical field investigations of the ductile deformation of coarse grained synthetic rock salt at room and high temperatures. We applied in situ optical (OM) and scanning electron microscopy (SEM) and X-ray micro-tomography (MCT) during uniaxial compression up to 10 % shortening. Digital surface image and digital volume correlation (DIC and DVC) techniques allowed characterizing and quantifying the multiscale organization of 2D and 3D full strain fields. The same localization patterns are observed in 2 and 3D: the macroscopic shear bands appearing at the sample scale refine into mesoscopic localization bands at the aggregate microstructure scale. The highest resolution investigations clearly demonstrate that the latter result from the concomitant and co-operative interplay between dominant crystal slip plasticity (CSP) and minor but necessary interfacial mechanisms, such as grain boundary sliding (GBS), migration, micro-cracking and cavitation. The quantitative analysis of the interfacial mechanism activity evidence only a modest contribution of less than 10 % to the overall strain, but without the latter development of ductile localization could not occur. The interfacial mechanisms (as GBS) are absolutely necessary to accommodate for the plastic strain incompatibilities among neighboring grains, related to the intrinsic anisotropy of CSP. To conclude, the coupling of CSP and interfacial mechanisms is immediate, right at the onset of ductile deformation. Our major conclusion is that during ductile localization in rocks CSP and GBS act as co-operative mechanisms due to the pronounced plastic anisotropy of minerals. At the beginning CSP appears to be the principal strain mechanism, but GBS happens to be best necessary and supporting one. We further suggest for mylonite development that once grain size reduction and phase mixing had occurred, GBS may become the principal actor, allowing for dominant Newtonian rheology and enhancement of localization.
• On adhesive theories in multilayered interfaces, with particular regard to "surface force apparatus" geometry
  
  • Tricarico Michele
  • Papangelo Antonio
  • Constantinescu Andrei
  • Ciavarella Michele
  Facta Universitatis, Series: Mechanical Engineering, 2019, 17 (1), pp.95. Adhesion is a key factor in many tribological processes, especially wear. We generalize a recent formulation for the indentation of a multilayered material using an efficient integral transform method, to the case of adhesion, using a simple energetic transformation in the JKR regime. Then, we specialize the study for the geometry of the Surface Force Apparatus, which consists of two thin layers on a substrate, where the intermediate layer is softer than the other two. We find the pull-off force under "force control" (i.e. for "soft" loading systems), as well as under "displacement control" (i.e. for "rigid" systems), as a function of the geometrical thicknesses and material properties ratios, and the method is fully implemented in a fast Mathematica code, available to the public. (10.22190/FUME190118011T)
  DOI : 10.22190/FUME190118011T
• Combination of Traction Assays and Multiphoton Imaging to Quantify Skin Biomechanics
  
  • Bancelin Stéphane
  • Lynch Barbara
  • Bonod-Bidaud Christelle
  • Dokládal Petr
  • Ruggiero Florence
  • Allain Jean-Marc
  • Schanne-Klein Marie-Claire
  , 2019, 1944, pp.145-155. An important issue in tissue biomechanics is to decipher the relationship between the mechanical behavior at macroscopic scale and the organization of the collagen fiber network at microscopic scale. Here, we present a protocol to combine traction assays with multiphoton microscopy in ex vivo murine skin. This multiscale approach provides simultaneously the stress/stretch response of a skin biopsy and the collagen reorganization in the dermis by use of second harmonic generation (SHG) signals and appropriate image processing. (10.1007/978-1-4939-9095-5_11)
  DOI : 10.1007/978-1-4939-9095-5_11
• A fully equilibrated microsphere model with damage for rubberlike materials
  
  • Diani J.
  • Le Tallec Patrick
  Journal of the Mechanics and Physics of Solids, Elsevier, 2019, 124, pp.702-713. A non-affine microsphere model for rubberlike materials is proposed, based on a local minimization of the network free energy under a maximal advance path constraint. It accounts for any chain weight distribution and for damage such as Mullins softening observed in filled rubber materials. The non-affine equal-force model is compared to the common affine model and a hybrid equal-force model from the literature, when considering the isotropic hyperelastic behavior without damage of rubber materials presenting chains of various lengths. The non-affine model shows an improved deformability compared to the affine model limited by the maximal extension of the shorter chains and a significantly softer behavior. Possible damage is introduced by increasing the chain lengths according to the submitted maximal chain traction force. Each chain are impacted independently resulting in a directional softening that introduces the evolution of the stress-free configuration that needs to be assessed over the loadings. The model was successfully tested on the cyclic uniaxial tension stretch-stress responses of carbon-black filled styrene butadiene rubbers that were well fitted with three parameters only. (10.1016/j.jmps.2018.11.021)
  DOI : 10.1016/j.jmps.2018.11.021
• Programmable higher-order Euler buckling modes in hierarchical beams
  
  • Tarantino M.G. G
  • Danas K.
  International Journal of Solids and Structures, Elsevier, 2019. We present a numerical-aided experimental study on the buckling of hierarchical beams comprising multiple self-similar modules. Each module consists of multiple elemental beams and is arranged in series to form the hierarchical beam. We show, through a combination of experiments and computations, that these beams exhibit stable and realizable higher-order buckling modes. By contrast to the canonical Euler buckling problem, such modes emerge naturally in the proposed self-similar beams since they correspond to almost identical critical loads. By harnessing the imperfection sensitivity of the hierarchical structures, we 3D-print weakly imperfect polymer samples with a small geometric imperfection corresponding to the desired eigenmode. We subsequently carry out uniaxial compression experiments and show in practice that higher-order patterns can be triggered selectively upon buckling. Moreover, these patterns are preserved in the post-bifurcation regime in many cases and are reversible upon load release. The ability to trigger higher-order buckling modes is found to depend on two main geometrical parameters which lead to scale coupling. Those are the slenderness of the macroscopic hierarchical beam and the slenderness of the lower-scale elemental beam. With increasing slenderness of the hierarchical beam, we observe a significant softening in the overall stress-strain response and patterns exhibiting curvature lo-calization in the post-bifurcation regime. The numerical finite-strain simulations carried out in the present study are found to be in very good agreement with the experiments and are used to quantify further the observed curvature localization in the hierarchical beams. The present study and the obtained results are geometric in nature and thus can be extended to different scales and hierarchies ad infinitum. (10.1016/j.ijsolstr.2019.03.009)
  DOI : 10.1016/j.ijsolstr.2019.03.009
• Functionality of Disorder in Muscle Mechanics
  
  • Borja da Rocha Hudson
  • Truskinovsky Lev
  Physical Review Letters, American Physical Society, 2019, 122 (8), pp.088103. A salient feature of skeletal muscles is their ability to take up an applied slack in a microsecond timescale. Behind this fast adaptation is a collective folding in a bundle of elastically interacting bistable elements. Since this interaction has a long-range character, the behavior of the system in force and length controlled ensembles is different; in particular, it can have two distinct order-disorder–type critical points. We show that the account of the disregistry between myosin and actin filaments places the elementary force-producing units of skeletal muscles close to both such critical points. The ensuing “double criticality” contributes to the system’s ability to perform robustly and suggests that the disregistry is functional. (10.1103/PhysRevLett.122.088103)
  DOI : 10.1103/PhysRevLett.122.088103
• Equilibrium unzipping at finite temperature
  
  • Borja da Rocha Hudson
  • Truskinovsky Lev
  Archive of Applied Mechanics, Springer Verlag, 2019, 89 (3), pp.535-544. We study thermally activated unzipping, which is modeled as a debonding process. The system is modeled as a parallel bundle of elastically interacting breakable units loaded through a series spring. Using equilibrium statistical mechanics, we compute the reversible response of this mechanical system under quasi-static driving. Depending on the stiffness of the series spring, the system exhibits either ductile behavior, characterized by noncoopera-tive debonding, or brittle behavior, with a highly correlated detachment of the whole bundle. We show that the ductile to brittle transition is of the second order and that it can also be controlled by temperature. (10.1007/s00419-018-1485-4)
  DOI : 10.1007/s00419-018-1485-4
• Validation of Finite Element Image Registration-based Cardiac Strain Estimation from Magnetic Resonance Images
  
  • Berberoglu Ezgi
  • Stoeck Christian T
  • Moireau Philippe
  • Kozerke Sebastian
  • Genet Martin
  , 2019. Accurate assessment of regional and global function of the heart is an important readout for the diagnosis and routine evaluation of cardiac patients. Indeed, recent clinical and experimental studies suggest that compared to global metrics, regional measures of function could allow for more accurate diagnosis and early intervention for many cardiac diseases. Although global strain measures derived from tagged magnetic resonance (MR) imaging have been shown to be reproducible for the majority of image registration techniques, the measurement of regional heterogeneity of strain is less robust. Moreover, radial strain is underestimated with the current techniques even globally. Finite element (FE)-based techniques offer a mechanistic approach for the regularization of the ill-posed registration problem. This paper presents the validation of a recently proposed FE-based image registration method with mechanical regularization named equilibrated warping. For this purpose, synthetic 3D-tagged MR images are generated from a reference biomechanical model of the left ventricle (LV). The performance of the registration algorithm is consequently tested on the images with different signal-to-noise ratios (SNRs), revealing the robustness of the method. (10.1002/pamm.201900418)
  DOI : 10.1002/pamm.201900418
• Medical images registration with finite elements and mechanical regularization
  
  • Genet Martin
  , 2019.
• Force-induced repolarization of an active crawler
  
  • Recho Pierre
  • Putelat Thibaut
  • Truskinovsky Lev
  New Journal of Physics, Institute of Physics: Open Access Journals, 2019, 21. We develop a quantitative model of mechanical repolarization in a contraction-driven gel layer mimicking a crawling cell. We show that the force-velocity relations for such active crawlers exhibit multi-valuedness and hysteresis under both force and velocity control. The model predicts steady oscillations of cells attached to an elastic environment and offers a selfconsistent mechanical explanation for all experimentally observed outcomes of cell collision tests. (10.1088/1367-2630/ab05fd)
  DOI : 10.1088/1367-2630/ab05fd
• Analysis and calibration of a linear model for structured cell populations with unidirectional motion : Application to the morphogenesis of ovarian follicles
  
  • Clément Frédérique
  • Robin Frédérique
  • Yvinec Romain
  SIAM Journal on Applied Mathematics, Society for Industrial and Applied Mathematics, 2019, 79 (1), pp.207-229. We analyze a multi-type age dependent model for cell populations subject to unidirectional motion, in both a stochastic and deterministic framework. Cells are distributed into successive layers; they may divide and move irreversibly from one layer to the next. We adapt results on the large-time convergence of PDE systems and branching processes to our context, where the Perron-Frobenius or Krein-Rutman theorem cannot be applied. We derive explicit analytical formulas for the asymptotic cell number moments, and the stable age distribution. We illustrate these results numerically and we apply them to the study of the morphodynamics of ovarian follicles. We prove the structural parameter identifiability of our model in the case of age independent division rates. Using a set of experimental biological data, we estimate the model parameters to fit the changes in the cell numbers in each layer during the early stages of follicle development. (10.1137/17M1161336)
  DOI : 10.1137/17M1161336
• Representative volume elements for the simulation of isotropic composites highly filled with monosized spheres
  
  • de Francqueville Foucault
  • Gilormini Pierre
  • Diani Julie
  International Journal of Solids and Structures, Elsevier, 2019, 158, pp.277-286. A method is proposed for generating reliable representative volume elements (RVEs) that allows reducing the statistical analysis required for the simulation of the mechanical behavior of isotropic composites highly filled with monosized spheres. The method combines (i) an algorithm inspired from molecular dynamics and associated with an analytical equation of state, and (ii) a geometrical analysis using the two-point correlation function and a nearest-neighbor distribution function. A restrictive selection process is defined, which leads to microstructures reasonably close to randomness and isotropy. The pertinence of the proposed generation and selection of RVEs is confirmed by the simulation of their elastic behavior with the nite element method. In particular, it is shown how the selection procedure allows reducing the computational e ort required to reach reliable elastic moduli by operating on a limited number of suitable RVEs. The results are in good agreement with the generalized self-consistent model and with original experimental data obtained on a composite where an acrylate matrix was reinforced by sifted glass beads. (10.1016/j.ijsolstr.2018.09.013)
  DOI : 10.1016/j.ijsolstr.2018.09.013
• Prediction of irradiation hardening Reactor Pressure Vessel steels: Multiscale modeling of crystal plasticity
  
  • Monnet G
  • Vincent Ludovic
  • Gelebart Lionel
  Journal of Nuclear Materials, Elsevier, 2019, 514, pp.128-138. (10.1016/j.jnucmat.2018.11.028)
  DOI : 10.1016/j.jnucmat.2018.11.028
• Mathematical modelling and numerical simulation of elastic wave propagation in soft tissues with application to cardiac elastography
  
  • Caforio Federica
  , 2019. This PhD thesis concerns the mathematical modelling and numerical simulation of impulsive Acoustic Radiation Force (ARF)-driven Shear Wave Elastography (SWE) imaging in a prestressed soft tissue, with a specific reference to the cardiac setting. The first part of the manuscript deals with the mathematical modelling of the ARF, the resulting shear wave propagation, and the characterisation of the shear wave velocity in a general constitutive law for the myocardial tissue. We also show some applications to the extraction of fibre orientation in the myocardium and the detection of “synthetic pathologies”. One of the main contributions of this work is the derivation of an original mathematical model of the ARF. In more detail, starting from an accurate biomechanical model of the heart, and based on asymptotic analysis, we infer the governing equation of the pressure and the shear wave field remotely induced by the ARF, and we compute an analytical expression of the source term responsible for the generation of shear waves from an acoustic pressure pulse. In the second part of the PhD thesis, we propose efficient numerical tools for a realistic numerical simulation of an SWE experiment in a nearly-incompressible, pre-stressed, fibered soft tissue. The spatial discretisation is based on high-order Spectral Finite Elements (HO-SEM). Concerning the time discretisation, we propose a novel method adapted to incompressible elasticity. In particular, only the terms travelling at infinite velocity, associated with the incompressibility constraint, are treated implicitly by solving a scalar Poisson problem at each time step of the algorithm. Furthermore, we provide a novel matrix-free, high-order, fast method to solve the Poisson problem, based on the use of the Discrete Fourier Transform.
• Identification d’un modèle orthotrope viscoplastique de comportement de l’alliage aéronautique Ti-6Al-4V
  
  • Ruiz de Sotto Miguel
  • Doquet Véronique
  • Longère Patrice
  • Papasidero Jessica
  , 2019.
• An Evolving Switching Surface Model for Ferromagnetic Hysteresis
  
  • Mukherjee D.
  • Danas K.
  Journal of Applied Physics, American Institute of Physics, 2019, 125 (3), pp.033902. We propose a thermodynamically consistent rate-independent three-dimensional model of magnetic hysteresis in terms of energetic and dissipation potentials making use of a relatively small number of model parameters that is capable of being implemented in a general incremental numerical setting. The dissipation process occurring during magnetization/demagnetization is described by a power-law potential, which leads to rate-independence at a certain limit of the rate-dependent exponent. The incorporation of isotropic hardening in the model enables us to describe phenomenologically at the macroscopic scale both nucleation and pinning type constitutive responses. We further model the symmetric and asymmetric minor loops by employing the idea of a bounding surface, which was originally introduced in the context of mechanical plasticity. Our model shows a very good agreement with experiments for spark plasma sintered NdFeB magnets, where nucleation is found to be the primary mechanism of coercivity. We also use our model to probe experiments for melt-spun NdFeB ribbons and powders, where both nucleation and pinning mechanisms are experimentally found to be significant. Moreover, we correlate the proposed model parameters with the underlying mechanisms for coercivity. Finally, we probe the predictive capability of the proposed model by first fitting an experimental minor loop, and then use it to successfully predict the remaining minor loops, obtained from that experiment. We also construct a FORC diagram for the floppy disc material and compare it with the corresponding experimental data. (10.1063/1.5051483)
  DOI : 10.1063/1.5051483
• Critical strain energy release rate for rubbers: single edge notch tension versus pure shear tests
  
  • Roucou David
  • Diani Julie
  • Brieu Mathias
  • Mbiakop-Ngassa Armel
  International Journal of Fracture, Springer Verlag, 2019.
• Gradient damage models coupled with plasticity and their application to dynamic fragmentation
  
  • Fischer Arthur Geromel
  • Marigo Jean-Jacques
  , 2019, pp.chapter 3, pp. 95-141. This chapter explains the development of the so‐called "gradient damage models" and their extension to ductile materials and dynamic loading. It presents the construction of gradient damage models for brittle softening materials based on the principle of minimum energy. The chapter discusses the main hypothesis and the need for regularization. It then briefly discusses the von Mises plasticity criterion and how to take it into account. The chapter briefly discusses the numerical implementation and shows a few examples and results using the FEniCS library and an industrial code. It considers the case of small strains theory and an isotropic material. The chapter reviews variational approach used to describe damage evolution for a quasi‐static loading. It expresses that the evolution of the plasticity minimizes the energy. The chapter concerns the study of the fragmentation of a cylinder under a strong internal pressure. (10.1002/9781119579311.ch3)
  DOI : 10.1002/9781119579311.ch3
• Influence of as-cast spherulites on the fracture toughness of a Zr 55 Cu 30 Al 10 Ni 5 bulk metallic glass
  
  • Hin S.
  • Bernard C.
  • Doquet V.
  • Yokoyama Y.
  • Magueresse A.
  • Keryvin V.
  Materials Science and Engineering: A, Elsevier, 2019, A 740-741, pp.137-147. (10.1016/j.msea.2018.10.061)
  DOI : 10.1016/j.msea.2018.10.061
• Role of medical reaction in management of inappropriate ventricular arrhythmia diagnosis: the inappropriate Therapy and HOme monitoRiNg (THORN) registry
  
  • Perrin Tilman
  • Boveda Serge
  • Defaye Pascal
  • Rosier Arnaud
  • Sadoul Nicolas
  • Bordachar Pierre
  • Klug Didier
  • Ritter Philippe
  • Belhameche Mohamed
  • Babuty Dominique
  • Mansourati Jacques
  • Lazarus Arnaud
  • Deharo Pierre
  EP-Europace, Oxford University Press (OUP), 2019, 21 (4), pp.607-615. (10.1093/europace/euy284)
  DOI : 10.1093/europace/euy284
• Monitoring dynamic collagen reorganization during skin stretching with fast polarization‐resolved second harmonic generation imaging
  
  • Ducourthial Guillaume
  • Affagard Jean‐sébastien
  • Schmeltz Margaux
  • Solinas Xavier
  • Lopez‐poncelas Maeva
  • Bonod‐bidaud Christelle
  • Rubio‐amador Ruth
  • Ruggiero Florence
  • Allain Jean-Marc
  • Beaurepaire Emmanuel
  • Schanne-Klein Marie-Claire
  Journal of Biophotonics, Wiley, 2019, 12 (5), pp.e201800336. The mechanical properties of biological tissues are strongly correlated to the specific distribution of their collagen fibers. Monitoring the dynamic reorganization of the collagen network during mechanical stretching is however a technical challenge because it requires mapping orientation of collagen fibers in a thick and deforming sample. In this work, a fast polarization-resolved SHG microscope is implemented to map collagen orientation during mechanical assays. This system is based on line-to-line switching of polarization using an electro-optical modulator and works in epidetection geometry. After proper calibration, it successfully highlights the collagen dynamic alignment along the traction direction in ex vivo murine skin dermis. This microstructure reorganization is quantified by the entropy of the collagen orientation distribution as a function of the stretch ratio. It exhibits a linear behavior, whose slope is measured with a good accuracy. This approach can be generalized to probe a variety of dynamic processes in thick tissues. (10.1002/jbio.201800336)
  DOI : 10.1002/jbio.201800336
• Multiscale characterization of skin mechanics through in situ imaging
  
  • Allain Jean-Marc
  • Lynch Barbara
  • Schanne-Klein Marie-Claire
  , 2019, 22, pp.265-280. The complex mechanical properties of skin have been studied intensively over the past decades. They are intrinsically linked to the structure of the skin at several length scales, from the macroscopic layers (epidermis, dermis and hypodermis) down to the microstructural organization at the molecular level. Understanding the link between this microscopic organization and the mechanical properties is of significant interest in the cosmetic and medical fields. Nevertheless, it only recently became possible to directly visualize the skin’s microstructure during mechanical assays, carried out on the whole tissue or on isolated layers. These recent observations have provided novel information on the role of structural components of the skin in its mechanical properties, mainly the collagen fibers in the dermis, while the contribution of others, such as elastin fibers, remains elusive. In this chapter we present current methods used to observe skin’s microstructure during a mechanical assay, along with their strengths and limitations, and we review the unique information they provide on the link between structure and function of the skin. (10.1007/978-3-030-13279-8_8)
  DOI : 10.1007/978-3-030-13279-8_8
• One-dimensional modeling of necking in rate-dependent materials
  
  • Audoly Basile
  • Hutchinson John
  Journal of the Mechanics and Physics of Solids, Elsevier, 2019, 123, pp.149. This paper presents an asymptotically rigorous one-dimensional analytical formulation capable of accurately capturing the stress and strain distributions that develop within the evolving neck of bars and sheets of rate-dependent materials stretched in tension. The work is an extension of an earlier study by the authors on necking instabilities in rate-independent materials. The one-dimensional model accounts for the gradients of the stress and strain that develop as the necking instability grows. Material strain-rate dependence has a significant influence on the strain that can be imposed on a bar or sheet before necking becomes pronounced. The formulation in this paper enables a quantitative assessment of the interplay in necking retardation due to rate-dependence and that due to the development of hydrostatic tension in the neck. The connection with a much simpler long-wavelength approximation which does not account for curvature induced hydrostatic tension in the neck is also emphasized and extended. (10.1016/j.jmps.2018.08.005)
  DOI : 10.1016/j.jmps.2018.08.005
• 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
• Ultrafine versus coarse grained Al 5083 alloys: From low-cycle to very-high-cycle fatigue
  
  • Li Meng
  • Goyal Anchal
  • Doquet Véronique
  • Ranc Nicolas
  • Couzinié Jean-Philippe
  International Journal of Fatigue, Elsevier, 2019, 121, pp.84-97. The fatigue performance of coarse and ultrafine-grained (UFG) 5083 Al alloy were compared, from low to very high cycle fatigue. The UFG alloy exhibited cyclic hardening and predominant kinematic hardening. At high plastic strain amplitude (and only in this regime), it showed easier crack initiation and a lower fatigue resistance. Its resistance to HCF was hardly better than that of its coarse grained counterpart until 2.10 6 cycles, but 43% higher in VHCF, until 5.10 8 cycles. Beyond that point, internal crack initiation occurred, and the fatigue resistance of the UFG material decreased, which was explained using Fracture Mechanics. (10.1016/j.ijfatigue.2018.12.004)
  DOI : 10.1016/j.ijfatigue.2018.12.004