Pilvin Philippe

Verified

Pilvin verified their affiliation via an institutional email.

Learn more

Verified

Pilvin verified their affiliation via an institutional email.

Learn more

• PhD
• Professor at University of Southern Brittany

Round tensile test specimens of an age-hardened CuCr1Zr alloy were subjected to direct electrical current heating in a Gleeble thermal–mechanical simulator at 800 °C. The mechanical properties were monitored by the Vickers hardness test, and the changes in the grain structure were examined by light metallography. A quantitative analysis of the size...

During normal operating conditions, zirconium alloy nuclear fuel cladding tubes experience various biaxial loadings with complex strain path histories. Experiments have been conducted on neutron-irradiated thin cladding tubes in order to study the response to changes in the loading path. These tests consist of alternate internal pressure tests and...

Polycrystals heterogeneities generate stress concentration which can be responsible for premature failure of mechanical parts and thereby need to be considered in mechanical models. A grain’s close neighborhood has shown to significantly impact its mechanical behavior. The more the crystal is anisotropic, the more this impact can be, which in some...

Needs for new particle based heterogeneous materials as led to the development of many Statistical Volume Element (SVE) modeling schemes tailored to specific shapes of particles or meshing procedures. To generalize the numerical analysis of particle filled SVEs, a modeling methodology based on the Unified Topology Model (UTM) is proposed. Using the...

Multipass arc welding is commonly used for thick plates assemblies in shipbuilding. Sever thermal cycles induced by the process generate inhomogeneous plastic deformation and residual stresses. Metallurgical transformations contribute at each pass to the residual stress evolution. Since residual stresses can be detrimental to the performance of the...

Due to aerodynamic instabilities induced by combination of rain and wind, civil engineering cables are submitted to cyclic loadings during their whole operating life. To prevent them from fatigue issues, internal and external dampers are increasingly used. Recently, innovative damping devices based on Shape Memory Alloys have demonstrated a true ef...

The well-known martensitic transformation is not always the unique solid-solid phase change in NiTi shape memory alloys (SMA). For this material, R-phase can occur from both austenite and martensite. In some applications, macroscopic strain of the material can be limited to 2%. In these cases, R-phase contribution can not be neglected anymore when...

The present study aims at providing computations that can be used as reference solution to check mean-field nonlinear homogenization models for elastoviscoplastic constituents. These computations are based on finite element (FE) simulations of polycrystalline aggregates made of grains with hexagonal crystalline structure. A detailed statistical ana...

The elastoviscoplastic behavior of α Ti-alloys microstructures is simulated under dwell-fatigue loading in order to identify the favorable crack initiation sites. To aim this goal, a mathematical model is developed using Cellular Automata (CA) approach. Each α Ti-alloy microstructure is presented with a Cellular Automaton formed of 900 and 10,000 c...

In this paper, a mathematical model based on Cellular Automaton (CA) is developed for the micromechanical simulation of Ti-alloys microstructures under elastoplastic loading. Automata were formed of 900 cells in which each cell represents a hexagonal close packed (HCP) grain of a titanium polycrystalline microstructure. Each cell was associated wit...

The present work uses cellular automata (CA) for the micromechanical simulations of polycrystalline structures and provides interesting insights on the stress-strain localization in elastically anisotropic materials. CA model were applied to a hexagonal close packed (HCP) titanium polycrystalline microstructure where each grain is represented as a...

Resistance spot welding is a technique widely used by the automotive industry to assemble thin steel sheets. The cyclic thermo-mechanical loading associated with the accumulation of weld spots progressively deteriorates the electrodes. This study addresses the development of a comprehensive multi-physical model that describes the sequential deterio...

Zirconium alloys are widely used in the nuclear industry. Several components, such as cladding or guide tubes, undergo strong mechanical loading during and after their use inside the pressurized water reactors. The current requirements on higher fuel performances lead to the developing on new Zr based alloys exhibiting better mechanical properties....

The mechanical response of amorphous silica (or silica glass) under hydrostatic compression for very high pressures up to 25 GPa is modelled via an elastic-plastic constitutive equation (continuum mechanics framework).The material parameters appearing in the theory have been estimated from the ex situ experimental data from Rouxel et al. [Rouxel T,...

Le soudage par point est une technique largement utilisée par l’industrie automobile pour assembler des tôles minces en acier. Les sollicitations thermomécaniques cycliques associées à l’accumulation des points de soudage dégradent progressivement les électrodes. L’objectif de cette étude est le développement d’un modèle multi-physique couplé qui...

One of the main nuclear materials is the austenitic stainless steels, which have good ductility and toughness, high thermal expansion coefficients and a thermal conductivity lower than that of martensitic or ferritic steels. The 316L(N) austenitic stainless steel (X2CrNiMo17-12-2 with controlled nitrogen) is evaluated for structures such as the ves...

Les structures à câbles de génie civil sont soumises à de sévères sollicitations mécaniques dans un environnement extérieur agressif. En particulier, la fatigue et le fretting-fatigue sont dus à des phénomènes d’instabilités aérodynamiques, provoquant la mise en vibration transversale des câbles. Pour allonger la durée de vie des câbles, il est don...

Most of civil engineering cable structures are subjected to potential damages mainly due to dynamic oscillations induced by wind, rain or traffic. If vibration amplitudes of bridge cables for example are too high, it may cause a fatigue phenomenon. Recently, researches had been conducted dealing with the use of damping devices in order to reduce vi...

The first objective of this study is to characterise the physico-chemical and mechanical properties of thermoplastic elastomers (TPE) and their constituents. In parallel with the experimental study, a model describing the mechanical behaviour of such materials at room temperature and without damage is proposed. The composite materials studied in th...

The objective of this study, dealing with the physico-chemical and mechanical characterisation of isotactic polypropylene, is to develop at room-temperature, a pre-necking micromechanical behaviour model. Spherolites in the injected samples are of 40 μm mean diameter and do not have preferential orientation. This is also true for the monoclinical-t...

The constitutive equations based on polycrystalline models include information on the microstructure of the metallic materials and offer extended modelling capabilities with respect to macroscopic approaches. The purpose of this paper is to show that they can now be used in finite element calculations. The material is then modelled in each Gauss po...

De nombreux ouvrages de génie civil comportent des câbles. Ces structures représentent un important investissement pour les gestionnaires qui veillent, en particulier à leur durabilité et à la sécurité des usagers. Toutefois, ils sont soumis à de sévères chargements dynamiques qui provoquent leur dégradation au fil du temps. Les oscillations induit...

: Deformation-induced martensite in metastable austenitic steel was characterised by the grid nanoindentation method. Distribution of nanohardness was found out in specimens with different martensite volume fractions. Bimodal distribution of hardness was only slightly affected by the values obtained on or near γ-α’ phase boundary. This approach was...

Description Forty-two peer-reviewed papers cover the entire spectrum of zirconium metallurgy, from basic metallurgy to accidental conditions and transport, through fabrication, creep and growth, and corrosion and hydriding. Sections cover

This study investigates spherical indentation of plastically graded materials (PGMs). The hardness of these materials decreases with depth due to microstructural or compositional changes. To predict the behavior of PGM, the knowledge of the plastic properties of the surface and the substrate is necessary. In this work, the spherical indentation tec...

A consistent mechanical and transmission electron microscopy (TEM) database is proposed to discuss the consequences of dynamic strain ageing (DSA) on the temperature history memory effect observed under the cyclic loading of a 316LN austenitic stainless steel. Two DSA mechanisms have been identified in relation with two temperature regimes: the fir...

High strength zinc-coated steels are used for automotive applications when high corrosion resistance and weight reduction are required. Resistance spot welding is the main method to assembly auto body. Steel sheets are held together under pressure exerted by copper alloy electrodes which concentrate welding current and clamp the sheets together. Bu...

Cables used in civil engineering bridge has very low intrinsic damping rate which makes them particularly susceptible to vibration related to weather (wind, rain) and traffic. The associated displacement amplitudes are relatively small near the anchor (about 5 mm), as well as vibration frequencies (1-10 Hz). This may cause damage and affect the sus...

Journée Annuelle JA SF2M 2011, Nancy, 4-6 juillet 2011

Materials Science & Technology 2011, Colombus, Etats-Unis, 16-20 octobre 2011

The precipitation hardened CuCrZr alloy is used in fusion machines for the heat sink of intensely cooled plasma facing components (PFC) due to its good thermal and mechanical properties. Albeit, the feedback from its application in Tore Supra (French tokamak) showed that this alloy is very sensitive to hot tearing during electron beam welding. Hot...

Themechanical properties of a CuCr1Zr alloy weremeasuredwith the help of a Gleeble 3500 machine at temperatures ranging from 250 ◦C to 1000 ◦C. Some tensile tests were also performed at 20 ◦C. The measured data were first used to determine the thermal linear coefficient at different temperatures. The measured curves were then simulated with an elas...

L’alliage CuCrZr est utilisé dans les machines de fusion notamment pour des composants refroidis face au plasma, à cause de ses bonnes propriétés thermiques et mécaniques. Cependant, le retour d’expérience sur plusieurs tokamaks, et plus particulièrement Tore Supra en France, a montré que cet alliage est très sensible au phénomène de fissuration à...

Kinetics of deformation induced martensitic transformation in metastable austenitic AISI 301 steel was characterized by several techniques including classical light metallography, X-ray diffraction, neutron diffraction and electron back scattered diffraction. In order to characterize the martensitic transformation, several specimens were tensile pr...

Kinetics of deformation-induced martensitic transformation in metastable austenitic steel AISI 301 was characterized by several techniques including classical light metallography, scanning electron microscopy, X-ray diffraction, neutron diffraction and electron back scattered diffraction. In situ monitoring of magnetic properties, acoustic emission...

This paper deals with the numerical simulation of the deep drawing of a metastable austenitic stainless steel of AISI 304 type. A two-phase model of elastoviscoplastic type has been developed by Gallée et al. (2007) to take into account the martensitic transformation induced by plastic deformation during cold forming that can exhibit this stainless...

Experimental applications of two different approaches for interpretation of instrumented indentation experiments are proposed in this paper. The first approach is the application of methodology developed for spherical indentation based on models. The second approach is the application of inverse algorithm based on the minimization between experimen...

For several decades, the plastic deformation mechanisms of f.c.c. metals under cyclic loading have received considerable attention. The extensive work on this subject has gradually lead to the identification of the physical processes to be included in a formal scheme of fatigue behavior. Accordingly, we propose a review of the physical mechanisms o...

The mechanical properties of metastable austenitic steel corresponding to the AISI301 were characterized by means of tensile testing and cupping tests. High sensitivity to the strain rate was observed. The fracture mechanism in tensile specimens changed from the combination of cleavage and ductile dimpled rupture at lower strain rates to entire duc...

We proposed an application of inverse approach to experimental indentation data in order to determine combined hardening models parameters. It was shown that the use of a model combining isotropic and kinematic hardening allows a better description of cyclic indentation than isotropic hardening models. It was also shown that inverse analysis applie...

Experimental applications of the methodology developed for spherical indentation are proposed in this paper. Two quasi-spherical indenters with different shapes were used in order to evaluate the stress–strain curve of five steels. Although the shape of the indenter was not perfectly spherical, it was shown that models developed for spherical inden...

An interpretation of spherical indentation experiments and the determination of hardening law parameters is the challenge in this paper. A new protocol based on multiple cyclic loading allowed models describing the indentation data changes to be determined from a numerical study. Inversion of these models, determined for two constitutive equations...

Anti-vibrating parts in automotives are often made of natural rubber reinforced by carbon black. This reinforcement, which comes from the filler–filler and filler–rubber interactions, leads to an increase of the elastic modulus, the tensile strength and the hysteresis. The aim of this work is to develop a model within a generalized self-consistent...

Antivibrating parts in automotives are often made of natural rubber reinforced by carbon black. This reinforcement, which comes from the filler–filler and filler–rubber interactions, leads to an increase in the elastic modulus, the tensile strength and the hysteresis. The aim of this work is to develop a micromechanical model within a generalised s...

The evolution of cyclic patterns during relaxation time has been studied in terms of long-range internal stresses and effective stress evolution as a function of time at 823 K. The main features are the decrease of intra-granular back stress in relation to dipole annihilation promoted by self-diffusion and a decrease of inter-granular back stress w...

L'objectif de cette etude est la caracterisation experimentale et la modelisation du comportement mecanique du polypropylene (PP). Des essais de caracterisation mecanique (traction, flexion et indentation) sont realises pour determiner le comportement du materiau. La loi de comportement macroscopique de ce polymere semi-cristallin est construite a...

The mechanical properties of metastable austenitic steel were characterized by means of tensile testing and cupping tests. High sensitivity to the strain rate was observed. The fracture mechanism in tensile specimens at the strain rate lower than ε =10 -3 s -1 was the combination of cleavage and ductile dimpled rupture. At the strain rate higher th...

The mechanical behaviour of a filled elastomer composed mainly of natural rubber reinforced by carbon black is investigated in the moderate elongation range, i.e. |Ε | < 0.4 in tension, compression and shear. Two types of carbon blacks, with different specific surfaces, are considerate. A micromechanical model is developed within a generalized self...

The work presented in this paper deals with the determination of material parameters used in internal variable constitutive models. In order to determine the best suited material parameter set, in the less computationally expensive way, two optimization approaches are used: (i) a gradient-based method and (ii) a continuous evolutionary algorithm (E...

The aim of this study is to conduct experimental characterization and to develop a micro-mechanical model for thermoplastic elastomers made of polypropylene and particles of rubber waste. Observations by means of Scanning Electron Microscope showed that the elastomer particles have an average dimension of 250 μm and are embedded in a polypropylene...

L objectif de cette étude est la caractérisation expérimentale et la modélisation du comportement mécanique de composites thermoplastiques élastomères (TPEs). Ils sont constitués d une matrice en polypropylène isotactique (PP) et de particules d élastomère recyclées en propylène diène monomère (EPDM). Le diamètre moyen de cellesci est de 67µm. La l...

Neutron radiation induces important changes in the mechanical behavior of recrystallized zirconium alloys used as fuel cladding tube. The neutron radiation effects on the mechanical behavior for internal pressure tests performed at 350 °C have been investigated using a specific analysis in terms of isotropic hardening, kinematic hardening and visco...

The aim of this study is to estimate residual stresses and distortions during the assembly of dissimilar metallic materials welded by Electron Beam Welding (EBW) technique. This work is motivated by a new welding procedure for the manufacture of large speed reduction gear. The gear consists of a central hub of S275 J2G3 steel and a toothed wheel of...

TEM investigations have been performed on irradiated samples after deformation covering various testing conditions for different recrystallized Zr alloys. It is shown that for transverse tensile tests and internal pressure tests performed at 350°C, only basal channels are observed for strain levels up to uniform elongation, whereas only prismatic a...

Un mod ele polycristallin est utilisé pour décrire le comportement mécanique d'un acier inoxydable austénitique de type AISI 316L. Une base de données expérimentale a ´ eté réalisée (essais de traction et de cisaillement) pour identifier la réponse du matériaù a diverses sollicitations elémentaires. Les résultats sont comparés avec des mod eles mac...

The purpose of this work is to investigate the frequency distributions of edge dipole heights in polycrystalline AISI 316L stainless steel cyclically deformed in the temperature range 300–873K. The effects of grain orientation, temperature and plastic strain rate on dislocation microstructure are discussed in terms of the dipole annihilation distan...

Finite element simulations of PLC effects in notched and CT (compact tensile) specimens of aluminium alloys are presented, based on a macroscopic PLC constitutive model. They predict the formation and propagation of intense strain rate localization bands. In particular, the predicted size of the plastic zone around the crack tip in a pre-cracked CT...

This paper deals with the characterization and the modelling of the mechanical behaviour of austenitic stainless steel that are commonly used in deep drawing processes. Some of these steels can exhibit a martensitic transformation at room temperature induced by the plastic deformation during cold forming. An experimental database has been establish...

La caractérisation expérimentale et la modélisation du comportement mécanique à l'état solide d'élastomères thermoplastiques (TPE) constitués d'une matrice en polypropylène isotactique (iPP) et de particules de caoutchouc recyclé sont présentées. L'observation au microscope électronique à balayage révèle que le matériau est constitué de particules...

Description Forty-one peer-reviewed papers cover all aspects of the fuel cycle. The Basic Metallurgy and Processing sections represent the beginning of the fuel cycle from component design and manufacture. The BWR Corrosion, PWR Corrosion, and Deformation Mechanism sections represent component performance under nominal service conditions. The Prima...

The aim of the present work is to use an available constitutive model for the description of the Portevin–Le Châtelier effect to simulate the deformation of notched specimens in tension (smooth and sharp U-notched specimens). This model can be used to account for dynamic strain ageing as suggested by Estrin et al. [Acta Mater. 49 (2000) 1087] but a...

Plastic deformation in irradiated zirconium alloys occurs in a very heterogeneous manner at the grain scale by the clearing up of radiation-induced prismatic loops by gliding dislocations and the channeling of these dislocations inside narrow bands of the grain. A statistical TEM investigation of this mechanism has been performed on neutron irradia...

This paper deals with the characterization and the modelling of the mechanical behavior of austenitic stainless steel that are commonly used in deep drawing processes. Some of these steels can exhibit a martensitic transformation at room temperature induced by the plastic deformation during cold forming, that have sometimes an unfavorable influence...

L'objectif de ce travail est l'identification de l'effet du procédé de mise en forme par hydroformage sur les caractéristiques des pièces en tantale ainsi obtenues. Il est apparu particulièrement important de pouvoir quantifier la conséquence de cette phase de fabrication, introduisant des déformations plastiques, sur l'évolution de la texture cris...

A polycrystalline model is proposed to model the large plastic deformation and texture evolutions in tantalum over a wide range of strain rates at room temperature. The mechanical behaviour is discussed in terms of back and effective stresses with the help of qualitative and quantitative TEM observations. Using these observations, an elasto-visco-p...

Les capacites predictives d'un modele phenomenologique macroscopique sont limitees par la base experimentale utilisee pour identifier le modele. Ainsi, pour ameliorer la description du comportement mecanique des tubes de gainage en alliages de zirconium, il est necessaire d'introduire de nouvelles donnees pour identifier completement l'anisotropie...

In this paper, we show the capabilities of a thermodynamicapproach to the relaxation of continuous media to describe the behaviorof the Nickel-based alloy IN738LC submitted to various mechanicalloadings at high temperature (850C). A preliminarysimple modeling (with one spectrum of relaxation times) does not providesatisfactory results. Microscopic...