References of "Detournay, Emmanuel"
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See detailEulerian Formulation of Elastic Rods
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2016), 472(2190),

In numerous biological, medical and engineering applications, elastic rods are constrained to deform inside or around tube-like surfaces. To solve efficiently this class of problems, the equations ... [more ▼]

In numerous biological, medical and engineering applications, elastic rods are constrained to deform inside or around tube-like surfaces. To solve efficiently this class of problems, the equations governing the deflection of elastic rods are reformulated within the Eulerian framework of this generic tubular constraint defined as a perfectly stiff canal surface. This reformulation hinges on describing the rod deformed configuration by means of its relative position with respect to a reference curve, defined as the axis or spine curve of the constraint, and on restating the rod local equilibrium in terms of the curvilinear coordinate parameterizing this curve. Associated with a segmentation strategy, which partitions the global problem into a sequence of rod segments either in continuous contact with the constraint or free of contact (except for their extremities), this approach not only trivializes the detection of new contacts but also suppresses the isoperimetric constraints resulting from the self-feeding feature of these elementary problems and the imposition of the rod position at the extremities of each rod segments. [less ▲]

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See detailSurface Constrained Elastic Rods with Application to the Sphere
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Journal of Elasticity (2016)

The unilateral contact between an elastic rod and a rigid surface is encountered in numerous biological and engineering applications. Along continuous contacts, the centerline of the rod reflects the ... [more ▼]

The unilateral contact between an elastic rod and a rigid surface is encountered in numerous biological and engineering applications. Along continuous contacts, the centerline of the rod reflects the geometry of the constraining surface. This restriction of the rod axis to surface bound configurations enters its local equilibrium through a reaction pressure which ensures the compatibility between the deformation and the restraint geometry. The classic equations governing the static equilibrium of elastic rods are particularized to surface bound configurations by (i) specifying the location of the rod axis in terms of its coordinates in the parameter space associated with the constraining surface parameterization, and (ii) characterizing the orientation of its material frame through its rotation with respect to the surface normal. This formulation, which emphasizes the relations between the rod configuration and the geometry of the constraint, also leads to an expression for the reaction pressure. This approach is then validated on a spherical surface by comparing with known solutions for elastic curves, i.e., inextensible and twist free rods. [less ▲]

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See detailConstrained Buckling of a Plane Elastica Inside a Frictional Conduit
Liakou, Anna; Denoël, Vincent ULg; Detournay, Emmanuel

Conference (2015)

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See detailDE3: Yet another high-order integration scheme for linear structural dynamics
Depouhon, Alexandre; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering. (2015)

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See detailNumerical simulation of percussive drilling
Depouhon, Alexandre; Denoël, Vincent ULg; Detournay, Emmanuel

in International Journal for Numerical and Analytical Methods in Geomechanics (2015), 39(8), 889-912

This paper presents a novel dynamical model to analyze the long-term response of a percussive drilling system. This departs from existing approaches that usually consider a single activation and bit/rock ... [more ▼]

This paper presents a novel dynamical model to analyze the long-term response of a percussive drilling system. This departs from existing approaches that usually consider a single activation and bit/rock interaction cycle for the analysis of the process performance. The proposed model integrates the axial dynamics of an elastic piston and an elastic drill bit, a motion-dependent pressure law to drive the piston, and a generalized bit/rock interaction law representative of the dynamic indentation taking place at the bit/rock interface. It applies to down-the-hole percussive drilling as well as top-hole, with minor modifications. The model does not account for the angular motion or the hole cleaning, however. The model is first formulated mathematically; then, a finite-dimensional approximation is proposed for computations. Numerical analyses of the model response, for a low-size down-the-hole percussive system, follow. The period-1 stationary response for the reference configuration is studied in detail, and parametric analyses assessing the influence on the rate of penetration of the bit/rock interaction parameters, the feed force, and the percussive activation parameters are conducted. These analyses reveal that the multiscale nature of the process is well captured by the model and recover expected trends for the influence of the parameters. They also suggest that a significant increase of the penetration rate can be achieved by increasing the percussive frequency. Copyright © 2015 John Wiley & Sons, Ltd [less ▲]

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See detailA Remark on the Poroelastic Center of Dilation
Huynen, Alexandre ULg; Detournay, Emmanuel

in Journal of Elasticity (2014), 116(2), 189-206

In the original derivation due to Dougall (1897), the center of dilation is constructed from the superposition of orthogonal force dipoles. However, it can also be built by combining dislocation dipoles ... [more ▼]

In the original derivation due to Dougall (1897), the center of dilation is constructed from the superposition of orthogonal force dipoles. However, it can also be built by combining dislocation dipoles. While the two representations are equivalent in elasticity, the different nature of the force and dislocation dipoles leads to different transient behaviors in poroelasticity, when the response evolves from undrained to drained. Indeed, we show that the poroelastic solution of a center of dilation is obtained by superposing the corresponding elastic solution and either an instantaneous fluid sink or an instantaneous fluid source, depending on whether the center of dilation is treated as a singular stress or displacement discontinuity. A simple explanation to the instantaneous injection or withdrawal of a finite volume of fluid from/to the singularity is given by adopting an exploded view of the poroelastic center of dilation. The exploration of the drained, undrained and transient responses of this singularity also requires to clarify the close relationship between an instantaneous fluid source and a continuous fluid dodecapole, an object constructed by collapsing onto a point three orthogonal pairs of fluid dipoles. [less ▲]

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See detailAspects of non-smooth dynamics in models of percussion
Depouhon, Alexandre; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the 8th European Nonlinear Dynamics Conference (2014, July 08)

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See detailEvent-driven integration of linear structural dynamics models under unilateral elastic constraints
Depouhon, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Computer Methods in Applied Mechanics & Engineering (2014), 276

This paper proposes an algorithm for the numerical simulation of linear structural dynamics problems under unilateral elastic constraints, i.e., constraints with a linear force/displacement characteristic ... [more ▼]

This paper proposes an algorithm for the numerical simulation of linear structural dynamics problems under unilateral elastic constraints, i.e., constraints with a linear force/displacement characteristic whenever active. The presented procedure relies on an event-driven strategy for the handling of the contact constraints, in combination with one-step schemes dedicated to the time integration of the second-order equations of motion. Efficiency of the procedure follows from the use of cubic Hermite interpolation to continuously extend the normal gap functions that reflect the openings of the contact interfaces. Robustness follows from the proper handling of complex numerical situations, e.g., numerical grazing or discontinuity sticking, through appropriate algorithm structure and numerical implementation. And, integration stability is guaranteed by the very nature of the algorithm and that of the one-step integration scheme. Following a detailed coverage of the integration procedure and the countermeasures to the expected numerical difficulties, three application examples are treated for illustration purposes. A MATLAB implementation of the procedure is provided online; download and usage information are given in the Appendix. [less ▲]

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See detailEulerian Formulation of the Torque and Drag Problem
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Detournay, Emmanuel; Denoël, Vincent; van de Wouw, Nathan (Eds.) Third International Colloquium on Nonlinear Dynamics and Control of Deep Drilling Systems (2014, May)

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See detailMultiscale aspects in modeling percussive drilling: from wave propagation to rigid body dynamics
Depouhon, Alexandre ULg; Denoël, Vincent ULg; Detournay, Emmanuel

in Proceedings of the 3rd International Colloquium on Nonlinear Dynamics and Control of Deep Drilling Systems (2014)

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See detailAccuracy of one-step integration schemes for damped/forced linear structural dynamics
Depouhon, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in International Journal for Numerical Methods in Engineering (2014)

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See detailNonlinear Dynamics and Control of Deep Drilling Systems
Detournay, Emmanuel; Denoël, Vincent ULg; van de Wouw, Nathan

Book published by College of Science and Engineering (2014)

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See detailAn efficient formulation for the simulation of elastic wave propagation in 1-dimensional collinding bodies
Depouhon, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the 11th International Conference on Vibration Problems (2013, September 09)

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See detailA drifting impact oscillator with periodic impulsive loading: Application to percussive drilling
Depouhon, Alexandre ULg; Denoël, Vincent ULg; Detournay, Emmanuel

in Physica D: Nonlinear Phenomena (2013), 258(0), 1--10

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See detailEulerian Formulation for an Extensible Elastic Rod
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Proceedings of the Fifth International Conference on Structural Engineering, Mechanics and Computation (2013, September)

This paper reformulates the governing equations of an extensible elastic rod by reference to a given spatial curve. This Eulerian formulation is motivated by the need to solve efficiently the constrained ... [more ▼]

This paper reformulates the governing equations of an extensible elastic rod by reference to a given spatial curve. This Eulerian formulation is motivated by the need to solve efficiently the constrained elastica problem encountered in many medical and engineering applications, in which a thin rod is inserted in a tortuous conduit. The Eulerian reformulation of the equations hinges on the restatement of the rod local equilibrium in terms of derivatives with respect to the curvilinear coordinate associated with the reference curve and the description of the rod deflection as a perturbation of this curve. The originality of the proposed formulation lays in the axially unconstrained character of the resulting system such that the determination of the rod configuration between two fixed points reduces to the resolution of a classical boundary value problem. [less ▲]

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See detailOn a modified bilinear law to model bit/rock interaction in percussive drilling
Depouhon, Alexandre ULg; Denoël, Vincent ULg; Detournay, Emmanuel

in Proceedings of the Nonlinear Dynamics in Engineering Conference (2013, August 21)

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See detailPoroelastic Center of Dilation Revisited
Huynen, Alexandre ULg; Detournay, Emmanuel

Conference given outside the academic context (2013)

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See detailPoroelastic Center of Dilation Revisited
Huynen, Alexandre ULg; Detournay, Emmanuel

in Hellmich, Christian; Pichler, Bernhard; Dietmar, Adam (Eds.) Poromechanics V: Proceedings of the Fifth Biot Conference on Poromechanics (2013, July)

A comparison of the original elastic solution for the center of dilation with the classic Lame ́ solution reveals an unexpected dependence of the center of dilation solu- tion on Poisson’s ratio. This ... [more ▼]

A comparison of the original elastic solution for the center of dilation with the classic Lame ́ solution reveals an unexpected dependence of the center of dilation solu- tion on Poisson’s ratio. This inconsistency is investigated by means of two alternative representations of the singularity which lead to the identification of a compressed zone inside the singularity. The poroelastic equivalent to this nucleus of strain is shown to be the superposition of the elastic one with drained material parameters and an instan- taneous point fluid source associated with a finite volume of fluid that is expelled from the compressed region inside the singularity and is injected in the porous medium. [less ▲]

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See detailInstability regimes and self-excited vibrations in deep drilling systems
Depouhon, Alexandre ULg; Detournay, Emmanuel

in Journal of Sound and Vibration (2013)

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See detailNonlinear Dynamics Of A Drill Bit Under Percussive Activation
Depouhon, Alexandre ULg; Denoël, Vincent ULg; Detournay, Emmanuel

in Proceedings of ICTAM 2012, Beijing (2012, August)

Detailed reference viewed: 59 (6 ULg)