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See detailAnisotropic damage model with initial stresses for microcracked materials
Levasseur, Séverine ULiege; Collin, Frédéric ULiege; Charlier, Robert ULiege et al

in Fifth International Conference on Advanced COmputational Methods in ENgineering (ACOMEN 2011) (2011)

In a recent study (Levasseur et al., 2010), we proposed a class of isotropic damage models which account for initial stresses. The present paper extends this approach to anisotropic damage due to growth ... [more ▼]

In a recent study (Levasseur et al., 2010), we proposed a class of isotropic damage models which account for initial stresses. The present paper extends this approach to anisotropic damage due to growth of an arbitrarily penny-shaped microcracks system. The basic principle of the upscaling technique in the presence of initial stress is first recalled. Then, we derive a closed-form expression of the elastic energy potential corresponding to a system of arbitrarily oriented microcracks. Thanks to the investigation of the influence of initial stresses on the material response under non monotonous loading paths, it is shown how the coupling between initial stresses and damage is strongly dependent of the microcracks density and orientation. In case of a particular distribution of microcracks orientation, described by a second order damage tensor, this model corresponds to a generalization of the macroscopic damage model of Halm and Dragon (1996), for which a physically-based interpretation can be proposed. [less ▲]

Detailed reference viewed: 39 (12 ULiège)
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See detailAnisotropic elasto-plastic finite element analysis using a stress-strain interpolation method based on a polycrystalline model
Habraken, Anne ULiege; Duchene, Laurent ULiege

in International Journal of Plasticity (2004), 20(Issue 8-9), 1525-1560

This paper describes a stress–strain interpolation method to model the macroscopic anisotropic elasto-plastic behavior of polycrystalline materials. Accurate analytical descriptions of yield loci derived ... [more ▼]

This paper describes a stress–strain interpolation method to model the macroscopic anisotropic elasto-plastic behavior of polycrystalline materials. Accurate analytical descriptions of yield loci derived from crystallographic texture [Int. J. Plasticity 19 (2003) 647; J. Phys. IV France 105 (2003) 39] are an interesting alternative to finite element models, where the macroscopic stress is provided by an averaging of microscopic stresses computed on a set of representative crystallites [Acta Metal 22 (1985) 923; Int. J. Plasticity 5 (1989) 67]. The parameters of the analytical functions modeling the yield locus are identified by comparison with a high number of stress tensors computed, for instance, by the well-known Taylor model [J. Inst. Metal 62 (1938) 307]. This identification method depends on the crystallographic texture and should be applied each time that the plastic strain has induced a significant texture evolution. The stress–strain interpolation method accurately describes the anisotropic material behavior in a narrow stress direction defined by only five stress points. The cost of texture updating is then greatly reduced compared to a full analytical function of the yield locus. After the mathematical description of the stress–strain interpolation method, its validity is demonstrated on two non-radial strain paths. The simulations of a deep drawing experiment allow comparing model predictions and measurements. Accuracy and CPU time of the interpolation stress–strain method are judged against two other models, respectively based on a complete analytical yield locus and on the averaging of crystallite stresses. [less ▲]

Detailed reference viewed: 76 (9 ULiège)
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See detailAnisotropic elastoplastic model based on texture
Habraken, Anne ULiege; Duchene, Laurent ULiege; Godinas, André et al

in Handbook of materials behavior models (2001)

Detailed reference viewed: 17 (9 ULiège)
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See detailAnisotropic Elastoplastic Model Based on Texture
Habraken, Anne ULiege

in Lemaitre Handbook of Materials Behavior Models (2001)

Detailed reference viewed: 17 (3 ULiège)
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See detailAnisotropic field percolation and high current density in 2212 Bi-based substituted with Dy bulk magnetically textured composite ceramics
Vanderbemden, Philippe ULiege; Vanderschueren, Hyacinthe ULiege; Stassen, Sophie et al

in Matsushita, T.; Yamafuji, K. (Eds.) Proceedings of the 8th International Workshop on Critical Currents in Superconductors (1996)

Detailed reference viewed: 27 (4 ULiège)
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See detailAnisotropic hydromechancial modelling of HGA field-scale experiment in Opalinus Clay
Levasseur, Séverine ULiege; Collin, Frédéric ULiege; François, Bertrand et al

Conference (2012)

Detailed reference viewed: 19 (2 ULiège)
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See detailAnisotropic modelling of Opalinus Clay behaviour: from triaxial tests to gallery excavation application
Bertrand, François ULiege; Collin, Frédéric ULiege

in Journal of Rock-Mechanics and Geotechnical Engineering (2017)

Deep repository in geological formations is the preferential solution considered by many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this ... [more ▼]

Deep repository in geological formations is the preferential solution considered by many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this context, in situ and laboratory tests are conducted on Opalinus Clay to demonstrate the feasibility of deep disposal in this argillaceous formation. This paper presents a constitutive model able to fit the experimental data obtained from some triaxial tests conducted by Jahns [1] on cores from bore hole Schlattingen SLA- 1. The elasto-plastic behaviour of Opalinus Clay is reproduced thanks to a Drucker-Prager model, taking into account the anisotropy behaviour of this sedimentary rock. The objective is to employ a single set of parameters representative of the material. In a second version of the model, the stress-dependency of the elastic properties and damage are taken into account. Finally, the parameters calibrated with experimental tests are used to simulate the excavation of a gallery with a second gradient approach. [less ▲]

Detailed reference viewed: 21 (1 ULiège)
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See detailAnisotropic Orientations of Polarisations from quasar light
Pelgrims, Vincent ULiege

Conference (2013, September)

Presentation of the foundations of a new statistical test dedicated to the polarisation orientations analysis.

Detailed reference viewed: 16 (3 ULiège)
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See detailAnisotropic resistivity tensor of melt-cast Bi2212 superconductors from QTA
Dellicour, Aline ULiege; Vertruyen, Bénédicte ULiege; Lutterotti, Luca et al

Conference (2014, August)

Detailed reference viewed: 26 (4 ULiège)
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See detailAnisotropic scaling in YBa2Cu3O7 crystals with columnar defects
Silhanek, Alejandro ULiege; Civale, L.

in Journal of Low Temperature Physics (2004), 135(1-2), 157-160

We explore the interplay between the mass anisotropy and the uniaxial pinning of tilted columnar defects (CD) in a YBa2Cu3O7 single crystal. At high temperatures T and fields H a sharp peak in the ... [more ▼]

We explore the interplay between the mass anisotropy and the uniaxial pinning of tilted columnar defects (CD) in a YBa2Cu3O7 single crystal. At high temperatures T and fields H a sharp peak in the irreversible magnetization M-i at the direction of the tracks signals the presence of the CD. At low T such a peak is not observed, and the influence of the CD appears only as a perturbation to the angular dependence due to the anisotropy. We show that at low T and high H the uniaxial effects due to CD can be recovered by performing an anisotropic rescaling. As expected, this scaling fails at low H. [less ▲]

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See detailAnisotropic yield locus of ultrafine-grained aluminium produced by Equal Channel angular extrusion
El Houdaigui, Fouad; Duchene, Laurent ULiege; Habraken, Anne ULiege et al

in Onate, E.; Owen, D. R. J. (Eds.) Proceedings of the VIII International Conference on Computational Plasticity (COMPLAS VIII) (2005)

Macroscopic tensile, compression and torsion tests have been performed as well as texture measurements. Based on these data a phenomenological yield locus has been defined to describe the behaviour of an ... [more ▼]

Macroscopic tensile, compression and torsion tests have been performed as well as texture measurements. Based on these data a phenomenological yield locus has been defined to describe the behaviour of an ultrafine-grained aluminum obtained by ECAE. [less ▲]

Detailed reference viewed: 130 (19 ULiège)
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See detailAnisotropie de la suceptibilité magnétique dans une intrusion composite de la suite charnockitique: l'apophyse du massif stratiforme de Bjerkreim-Sokndal (Rogaland, Norvège méridionale)
Bolle, Olivier ULiege; Diot, Hervé; Duchesne, Jean-Clair ULiege

in Comptes Rendus de l'Académie des Sciences. Série II, Mécanique, Physique, Chimie, Sciences de l'Univers, Sciences de la Terre (1997), 325

Detailed reference viewed: 44 (1 ULiège)
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See detailAnisotropies from polarization of quasars
Pelgrims, Vincent ULiege

Poster (2014, May)

Detailed reference viewed: 14 (0 ULiège)
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See detailAnisotropy and tension-compression asymmetry modeling of the room temperature plastic response of Ti-6A1-4V
Tuninetti, Victor; Gilles, Gaëtan ULiege; Pardoen, Thomas et al

in International Journal of Plasticity (2015), 67

The mechanical behavior of the alloy Ti-6A1-4V is characterized using uniaxial tension, uniaxial compression, simple shear and place strain tests in three orthogonal material directions. The experimental ... [more ▼]

The mechanical behavior of the alloy Ti-6A1-4V is characterized using uniaxial tension, uniaxial compression, simple shear and place strain tests in three orthogonal material directions. The experimental results reveal tension/compression asymmetry, anisotropic yielding and anisotropic strain-hardening. These features are incorporated into an elasto-plastic constitutive law based on the macroscopic orthotropic yield criterion "CPB06" adapted to hexagonal metals. A new identification method for the yield criterion parameters is proposed by inverse modeling of the axial strain field compression specimens in the three orthogonal directions of the material. The sensitivity of different sets of material parameters to the identification method is also analysed and the capacity of the model to accurately predict the forces and displacement field is discussed. A validation of the best set of identified CPB06material parameters is performed by comparing the load-displacement curves in different loading directions for tensile tests on notched round bars with different levels of stress triaxiality and for compression tests on elliptical cross-section specimens, both tests involving multiaxial strain fields and large deformations. [less ▲]

Detailed reference viewed: 82 (32 ULiège)
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See detailAnisotropy of Magnetic Susceptibility (AMS) study of deformation in the Bjerkreim-Sokndal layered intrusion (Rogaland, Southwest Norway)
Bolle, Olivier ULiege; Diot, Hervé; Duchesne, Jean-Clair ULiege

in Nordgulen, Øystein; Padget, Peter; Robinson, Peter (Eds.) et al COPENA conference at NGU, August 18-22, 1997: Abstract and Proceedings (1997)

Detailed reference viewed: 14 (0 ULiège)
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See detailAnisotropy of magnetic susceptibility in the Farsund charnockite (Southern Norway) reveals late-Sveconorwegian strike-slip ductile shearing
Bolle, Olivier ULiege; Diot, Hervé

in AGC/GAC – AMC/MAC – SEG – SGA Abstract Volume (2008), 33

Detailed reference viewed: 21 (3 ULiège)
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See detailANISOTROPY OF THE MIXED-STATE IN TEXTURED PB-FREE BI-2223 SUPERCONDUCTOR - ELECTRICAL-RESISTIVITY, SEEBECK AND NERNST EFFECTS
PEKALA, M.; Bougrine, Hassan ULiege; LADA, T. et al

in Superconductor Science & Technology (1995), 8(9), 726-739

Anisotropy of transport entropy and of Hall angle are reported for the first time through various electrical and thermal transport properties, such as the electric resistivity and the Seebeck and the ... [more ▼]

Anisotropy of transport entropy and of Hall angle are reported for the first time through various electrical and thermal transport properties, such as the electric resistivity and the Seebeck and the Nernst effects (in the presence of a magnetic field ranging between 0 and 4 T), measured for a Pb-free textured Bi-2223 system. The field and temperature influence in the mixed state region is reported only for the H parallel to a and H parallel to c cases and the temperature gradient applied along the b direction. A much stronger influence of magnetic field along the c than the a axis is demonstrated. The relative evolution of the so-called 'excess transport effects' is discussed. We show the laws relating the respective losses to the applied magnetic field. This leads us to the understanding that anisotropic vortex kinetics exist in these systems. We consequently propose two original routes of theoretical investigations to be considered for the calculation of Nernst and TEP effects in a field, in particular to consider a vortex-carrier drag phenomenon. [less ▲]

Detailed reference viewed: 21 (3 ULiège)