Publications

• Article dans une revue

A priori error analysis of the BEM with graded meshes for the electric field integral equation on polyhedral surfaces

A. Bespalov, Serge Nicaise

The Galerkin boundary element discretisations of the electric field integral equation (EFIE) on Lipschitz polyhedral surfaces suffer slow convergence rates when the underlying surface meshes are quasi-uniform and shape-regular. This is due to singular behaviour of the solution to this problem in…

Computers & Mathematics with Applications, 2016, 71 (8), pp.1636-1644. ⟨10.1016/j.camwa.2016.03.013⟩. ⟨hal-03135595⟩

• Thèse

Élaboration de céramiques polycristallines transparentes Er ³+ : YAG par Spark Plasma Sintering pour applications laser de puissance, Development of transparent polycrystalline Er ³+ : YAG ceramics by Spark Plasma Sintering for high power laser applications

Aurelien Katz

Cette étude s’intéresse à l’amélioration des performances du laser solide Er3+:YAG, dont la longueur d’onde de 1,64 µm est dite « eye-safe ». L’une des solutions est le remplacement des monocristaux actuellement utilisés comme milieu amplificateur par des céramiques polycristallines Er:YAG…, This work focus on the improvement of the solid state Er3+:YAG laser performances presenting an "eye-safe" wavelength at 1.64 µm. One way is the replacement of single crystals currently used as gain media by polycrystalline ceramics as they present improved thermo-mechanical properties…

Matériaux. Université de Valenciennes et du Hainaut-Cambresis, 2016. Français. ⟨NNT : 2016VALE0007⟩. ⟨tel-03224333⟩

• Communication dans un congrès

Développement de capteurs piezoélectriques interdigités flexibles pour la caractérisation ultrasonore des revêtements

Rafatou Takpara, Marc Duquennoy, Christian Courtois, Mohamed Rguiti

30èmes Journées Annuelles du Groupe Français de la Céramique, GFC 2016, Mar 2016, Valenciennes, France. ⟨hal-03591220⟩

• Article dans une revue

Discretization of the Poisson equation with non-smooth data and emphasis on non-convex domains

Thomas Apel, Serge Nicaise, Johannes Pfefferer

Several approaches are discussed how to understand the solution of the Dirichlet problem for the Poisson equation when the Dirichlet data are non-smooth such as if they are in L2 only. For the method of transposition (sometimes called very weak formulation) three spaces for the test functions are…

Numerical Methods for Partial Differential Equations, 2016, 32 (5), pp.1433-1454. ⟨10.1002/num.22057⟩. ⟨hal-03138821⟩

• Thèse

Revêtements sol-gel composites sur acier pour applications tribologiques, Composite sol-gel coatings on steel for tribological applications

Kurt Hermange

Ces travaux de thèse portent sur l’élaboration et la caractérisation de revêtements sol-gel composites ≪ CSG ≫ sur acier inoxydable austénitique AISI 304. L’objectif de la thèse était de mettre au point le procédé d'élaboration et d'étudier les propriétés mécaniques et le comportement…, This thesis focuses on the elaboration and the characterization of composite sol-gel coatings “CSG” on austenitic stainless steelAISI 304. The aim of the thesis is to develop the process and to study the mechanical properties and tribological behavior of thecoatings. The first experimental part…

Mécanique des matériaux [physics.class-ph]. Université de Valenciennes et du Hainaut-Cambresis, 2016. Français. ⟨NNT : 2016VALE0006⟩. ⟨tel-01484879⟩

• Communication dans un congrès

Surface canal, squelette et espace des sphères

Jean-Paul Becar, Sylvie Chambon, Bastien Durix, Lionel Garnier, Géraldine Morin, Céline Roudet

Une surface canal est l'enveloppe d'une famille à un paramètre de sphères orientées. Connaissant les fonctions de centre et de rayon associées à celle-ci, il est aisé d'obtenir une paramétrisation de la surface. Nous étudions dans cet article l'opération inverse, c'est-à-…, A canal surface is the envelope of a one-parameter familly of oriented spheres. With the knowledge of center an radius functions associated to it, it is easy to compute a parametrisation of the surface. In this article, we study the inverse operation, which is the search for the spheres in the…

Journées du Groupe de Travail en Modélisation Géométriq (GTMG 2016), CNRS; AFIG : Association Française d’Informatique Graphique; Chapitre Français d’Eurographics, Mar 2016, Dijon, France. ⟨hal-02508286⟩

• Article dans une revue

The Dirichlet problem for a prescribed anisotropic mean curvature equation

Chiara Corsato, Colette De Coster, Pierpaolo Omari

We discuss existence, uniqueness, regularity and boundary behaviour of solutions of the Dirichlet problem for the prescribed anisotropic mean curvature equation −div(∇u/1+|∇u|2)=−au+b/1+|∇u|2, where a,b>0 are given parameters and Ω is a bounded Lipschitz domain in RN. This equation appears in…

Journal of Differential Equations, 2016, 260 (5), pp.4572-4618. ⟨10.1016/j.jde.2015.11.024⟩. ⟨hal-03135815⟩

• Article dans une revue

Development of flexible SAW sensors for non-destructive testing of structure

Rafatou Takpara, Marc Duquennoy, Christian Courtois, Maurice Gonon, Mohammadi Ouaftouh, Gregory Martic, Mohamed Rguiti, Frédéric Jenot, Laurent Seronveaux, Christine Pelegris

In order to accurately examine structures surfaces, it is interesting to use surface SAW (Surface Acoustic Wave). Such waves are well suited for example to detect early emerging cracks or to test the quality of a coating. In addition, when coatings are thin or when emergent cracks are precocious,…

AIP Conference Proceedings, 2016, 1706 (1), ⟨10.1063/1.4940521⟩. ⟨hal-03119947⟩

• Article dans une revue

Curvature properties of some class of warped product manifolds

Ryszard Deszcz, Małgorzata Głogowska, Jan Jełowicki, Georges Zafindratafa

We prove that warped product manifolds with p-dimensional base, p=1,2, satisfy some pseudosymmetry type curvature conditions. These conditions are formed from the metric tensor g, the Riemann–Christoffel curvature tensor R, the Ricci tensor S and the Weyl conformal curvature C of the considered…

International Journal of Geometric Methods in Modern Physics, 2016, 13 (01), pp.1550135. ⟨10.1142/S0219887815501352⟩. ⟨hal-03148376⟩

• Article dans une revue

Fracture toughness of glasses and hydroxyapatite: a comparative study of 7 methods by using Vickers indenter

Isabel Hervas, Alex Montagne, Adrien van Gorp, M. Bentoumi, Anthony Thuault, Alain Iost

Numerous methods have been proposed to estimate the indentation fracture toughness Kic for brittle materials. These methods generally uses formulæ established from empirical correlations between critical applied force, or average crack length, and classical fracture mechanics tests. This study…

Ceramics International, 2016, 42 (11), pp.12740-12750. ⟨10.1016/j.ceramint.2016.05.030⟩. ⟨hal-01337280⟩