References of "Deliège, Geoffrey"
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See detailPFEM-FEM coupling for fluid-structure interaction problems involving free surfaces and large solid deformations
Cerquaglia, Marco Lucio ULiege; Boman, Romain ULiege; Deliège, Geoffrey ULiege et al

Conference (2017, June 14)

The present work focuses on the solution of fluid-structure interaction problems involving free surfaces and deformable structures. Free-surface flows are often encountered in reality, but the numerical ... [more ▼]

The present work focuses on the solution of fluid-structure interaction problems involving free surfaces and deformable structures. Free-surface flows are often encountered in reality, but the numerical solution of such problems remains a challenge, especially when the flow interacts with some flexible structure. The Particle Finite Element Method (PFEM) is nowadays a well-established Lagrangian method for the study of free-surface flows. The key feature of this method is the continuous remeshing of the computational domain through an efficient Delaunay triangulation, based on which the equations are solved using classical Finite Elements. In this work, the PFEM is coupled to Metafor, an in-house non-linear Finite Element solver, through an original partitioned strategy, based on block Gauss-Seidel iterations with dynamic relaxation. The main advantages of using a partitioned approach are that independent formulations can be employed for the fluid and the solid domains, and that the capabilities of already existing codes can be exploited at their best. In particular, in the problems proposed in this work, the solid structures can undergo very large deformations, and complex material laws, including plasticity for instance, can be easily taken into account. The techniques developed in this work are assessed through many examples, ranging from civil engineering problems, such as a dam break against a deformable obstacle, to aerospace applications, such a bird strike. Results are compared to those available in the literature, whenever possible. [less ▲]

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See detailThe particle finite element method for the numerical simulation of bird strike
Cerquaglia, Marco Lucio ULiege; Deliège, Geoffrey ULiege; Boman, Romain ULiege et al

in International Journal of Impact Engineering (2017)

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See detailPreliminary assessment of the possibilities of the Particle Finite Element Method in the numerical simulation of bird impact on aeronautical structures
Cerquaglia, Marco Lucio ULiege; Deliège, Geoffrey ULiege; Boman, Romain ULiege et al

in Procedia Engineering (2017), 173

As well known, in the analysis of bird impact events the bird is often reduced, even experimentally, to a surrogate projectile modeled as a weakly compressible fluid (typically a mixture of water and air ... [more ▼]

As well known, in the analysis of bird impact events the bird is often reduced, even experimentally, to a surrogate projectile modeled as a weakly compressible fluid (typically a mixture of water and air). From a numerical standpoint, the presence of a free surface and the strong interaction with the aircraft structures represent a limit for traditional computational fluid dynamics methods based on an Eulerian grid. On the other hand, classical Lagrangian methods cannot cope with the extremely large deformations experienced by the projectile during the impact. The Particle Finite Element Method (PFEM) is a Lagrangian particle method that can account for very large deformations, preserving the robustness and generality of the finite element method, and thus owning a key advantage over other approaches, e.g. Smoothed Particle Hydrodynamics (SPH), usually cursed with consistency and stability issues. To assess the possibilities of the method in the context of bird impact, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted. [less ▲]

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See detailTwo novel ways to impose free-slip boundary conditions in fluid-structure interaction problems using the Particle Finite Element Method
Cerquaglia, Marco Lucio ULiege; Deliège, Geoffrey ULiege; Boman, Romain ULiege et al

Conference (2016, June 09)

As well known, the imposition of boundary conditions is, in many cases, the trickiest part in solving differential problems, both from a physical and numerical standpoint. This work focuses on the way ... [more ▼]

As well known, the imposition of boundary conditions is, in many cases, the trickiest part in solving differential problems, both from a physical and numerical standpoint. This work focuses on the way boundary conditions are accounted for in the solution of fluid-structure interaction problems using the Particle Finite Element Method (PFEM). In particular, the PFEM traditionally employs no-slip conditions on the fluid-solid interfaces. Our aim is twofold. On the one hand, we demonstrate that, in the framework of the PFEM, the no-slip hypothesis is too strong in some cases, leading to erroneous physical results, and that a free-slip condition is to be preferred instead; we therefore propose two novel ways to impose free-slip conditions, devoting special attention to generality, simplicity and robustness. On the other hand, we show how the use of free-slip boundary conditions can also be beneficial with regards to two major problems arising from the remeshing procedure employed by the PFEM: the violation of the mass conservation principle and the introduction of spurious pressure oscillations. [less ▲]

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See detailFree-slip boundary conditions for simulating free-surface incompressible flows through the Particle Finite Element Method
Cerquaglia, Marco Lucio ULiege; Deliège, Geoffrey ULiege; Boman, Romain ULiege et al

in International Journal for Numerical Methods in Engineering (2016)

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See detailOn some drawbacks and possible improvements of a Lagrangian finite element approach for simulating incompressible flows
Cerquaglia, Marco Lucio ULiege; Deliège, Geoffrey ULiege; Boman, Romain ULiege et al

in Oñate, E.; Bischoff, M.; Owen, D.R.J. (Eds.) et al Proceedings of the IV International Conference on Particle-Based Methods – Fundamentals and Applications (2015)

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See detailAn effective finite-element-based method for the computation of nonlinear normal modes of nonconservative systems
Renson, Ludovic ULiege; Deliège, Geoffrey ULiege; Kerschen, Gaëtan ULiege

in Meccanica (2014), 49(8), 1901-1916

This paper addresses the numerical computation of nonlinear normal modes defined as two-dimensional invariant manifolds in phase space. A novel finite-element-based algorithm, combining the streamline ... [more ▼]

This paper addresses the numerical computation of nonlinear normal modes defined as two-dimensional invariant manifolds in phase space. A novel finite-element-based algorithm, combining the streamline upwind Petrov-Galerkin method with mesh moving and domain prediction-correction techniques, is proposed to solve the manifold-governing partial differential equations. It is first validated using conservative examples through the comparison with a reference solution given by numerical continuation. The algorithm is then demonstrated on nonconservative examples. [less ▲]

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See detailAn implicit erosion algorithm for the numerical simulation of metallic and composite materials submitted to high strain rate.
Ponthot, Jean-Philippe ULiege; Boman, Romain ULiege; Jeunechamps, Pierre-Paul et al

in Proceedings of the Indian National Science Academy (2013), 79/4(Part A), 519-528

In this paper, we present a general consistent numerical formulation able to take into account strain rate, damage and thermal effects of the material behaviour. A thermomechanical implicit approach for ... [more ▼]

In this paper, we present a general consistent numerical formulation able to take into account strain rate, damage and thermal effects of the material behaviour. A thermomechanical implicit approach for element erosion to model material failure is also presented. This approach can be applied both to ductile fracture for metals, relying on a continuum damage mechanics approach, coupled to different fracture criteria, as well as composite material failure described with either a failure criterion or a progressive damage model. The numerical models will be illustrated by different quasi-static and high strain rate applications for both metallic alloys and composite materials. All these physical phenomena have been included in an implicit dynamic object-oriented finite element code (implemented at LTAS-MN²L, University of Liège, Belgium) named Metafor [1]. [less ▲]

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See detailFinite element computation of nonlinear normal modes of nonconservative systems
Renson, Ludovic ULiege; Deliège, Geoffrey ULiege; Kerschen, Gaëtan ULiege

in Proceedings of the ISMA 2012 conference (2012, September)

Modal analysis, i.e., the computation of vibration modes of linear systems, is really quite sophisticated and advanced. Even though modal analysis served, and is still serving, the structural dynamics ... [more ▼]

Modal analysis, i.e., the computation of vibration modes of linear systems, is really quite sophisticated and advanced. Even though modal analysis served, and is still serving, the structural dynamics community for applications ranging from bridges to satellites, it is commonly accepted that nonlinearity is a frequent occurrence in engineering structures. Because modal analysis fails in the presence of nonlinear dynamical phenomena, the development of a practical nonlinear analog of modal analysis is the objective of this research. Progress in this direction has been made recently with the development of numerical techniques (harmonic balance, continuation of periodic solutions) for the computation of nonlinear normal modes (NNMs). Because these methods consider the conservative system, this study targets the computation of NNMs for nonconservative systems, i.e. defined as invariant manifolds in phase space. Specifically, a new finite element technique is proposed to solve the set of partial differential equations governing the manifold geometry. The algorithm is demonstrated using different two-degree-of-freedom systems. [less ▲]

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See detailFinite Element Computation of Nonlinear Normal Modes
Renson, Ludovic ULiege; Deliège, Geoffrey ULiege; Noels, Ludovic ULiege et al

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

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See detailImplicit FE simulations of composite dynamic failure
Deliège, Geoffrey ULiege; Papeleux, Luc ULiege; Ponthot, Jean-Philippe ULiege

in Proceedings of DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading (2009, September)

This paper describes the implementation of failure criteria in an implicit finite element code. Tests are made with the Tsai-Wu criterion, which is widely used in the simulation of composite failure. The ... [more ▼]

This paper describes the implementation of failure criteria in an implicit finite element code. Tests are made with the Tsai-Wu criterion, which is widely used in the simulation of composite failure. The method is applied to the simulation of a tensile test of a laminate composite. The elasto-plastic material model of the composite ply, a polymer reinforced with woven carbon fabric, is described. Convergence of the results with respect to the mesh size and number of time steps is analysed and the reliability of the method is discussed. [less ▲]

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See detailCrank-Nicolson Scheme for Solving Low Mach Number Unsteady Viscous Flows Using an Implicit Preconditioned Dual Time Stepping Technique
Vigneron, Didier ULiege; Deliège, Geoffrey ULiege; Essers, Jean-André ULiege

in Deconinck, Herman; Dick, Eric (Eds.) Computational Fluid Dynamics 2006 (2009)

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See detailIterative solvers and stabilisation for mixed electrostatic and magnetostatic formulations
Deliège, Geoffrey ULiege; Rosseel, Eveline; Vandewalle, Stefan

in Journal of Computational & Applied Mathematics (2008), 215(2), 348-356

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See detailAccuracy analysis of the thrust force in 2D-3D finite element models
Deliège, Geoffrey ULiege; Henrotte, François; Hameyer, Kay

in COMPEL (2006), 25(2), 320-333

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