References of "Journal of Computational & Applied Mathematics"
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See detailA variational framework for nonlinear viscoelastic models in finite deformation regime
Fancello, E. A.; Ponthot, Jean-Philippe ULg; Stainier, Laurent ULg

in Journal of Computational & Applied Mathematics (2005), 215(2), 400-408

This work presents a general framework for constitutive viscoelastic models in the finite deformation regime. The approach is qualified as variational since the constitutive updates consist of a ... [more ▼]

This work presents a general framework for constitutive viscoelastic models in the finite deformation regime. The approach is qualified as variational since the constitutive updates consist of a minimization problem within each load increment. The set of internal variables is strain-based and uses a multiplicative decomposition of strain in elastic and viscous components. Spectral decomposition is explored in order to accommodate, into analytically tractable expressions, a wide set of specific models. Moreover, it is shown that, through appropriate choices of the constitutive potentials, the proposed formulation is able to reproduce results obtained elsewhere in the literature. Finally, numerical examples are included to illustrate the characteristics of the present formulation. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailApplication of genetic algorithms to lubrication pump stacking design
Kelner, Vincent ULg; Léonard, Olivier ULg

in Journal of Computational & Applied Mathematics (2004), 168(1-févr Sp. Iss. SI), 255-265

Sizing a pump stacking used in an aircraft lubrication system is a challenging task. The combination of several pumps, in parallel and in a single casing, must deliver specified oil flow rates, on a ... [more ▼]

Sizing a pump stacking used in an aircraft lubrication system is a challenging task. The combination of several pumps, in parallel and in a single casing, must deliver specified oil flow rates, on a variable number of circuits, and under given flight conditions. Furthermore, the optimal assembly has to minimize overall dimensions, weight and cost. This optimization problem involves a large space search, continuous and discrete variables and multi-objectives. Genetic Algorithms (GA)-stochastic search methods that mimic the metaphor of natural biological evolution-seem well suited to solve that kind of problems. A new GA is proposed. The efficiency of this GA is first demonstrated in solving various mathematical test-cases and then applied to the industrial problem. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailMachining processes simulation : specific finite element aspects
Masset, Luc ULg; Debongnie, Jean-François ULg

in Journal of Computational & Applied Mathematics (2004, July 01), 168(1-2), 309-320

The paper presents a simulation tool designed to predict form errors of part surfaces obtained by face milling and turning processes. For these operations, the form error is often due to the flexibility ... [more ▼]

The paper presents a simulation tool designed to predict form errors of part surfaces obtained by face milling and turning processes. For these operations, the form error is often due to the flexibility of the workpiece and its supports. The finite element method is adopted to model the part geometry and to compute its deformations. Numerous load cases are required to obtain the form error so that classical resolution methods prove to be inefficient (CPU time, memory and disk space). The paper mainly focuses on the special computation scheme adopted in order to improve the resolution of such an atypical problem. [less ▲]

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See detailMulti-Harmonic Modelling of Motional Magnetic Field Problems using a Hybrid Finite Element--Boundary Element Discretisation
Gyselinck, J.; Geuzaine, Christophe ULg; Dular, Patrick ULg et al

in Journal of Computational & Applied Mathematics (2004), 168

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See detailModelling of electromagnetic waves in periodic media with finite elements
Nicolet, A.; Guenneau, S.; Geuzaine, Christophe ULg et al

in Journal of Computational & Applied Mathematics (2004), 168

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See detailApplication of the fast multipole method to hybrid finite element-boundary element models
V Sabariego, Ruth ULg; Gyselinck, Johan; Geuzaine, Christophe ULg et al

in Journal of Computational & Applied Mathematics (2004), 168(1-2), 403-412

This paper focuses on the acceleration of the hybrid finite element-boundary element analysis of 2D eddy current problems by means of the fast multipole method. An adaptive truncation scheme for the ... [more ▼]

This paper focuses on the acceleration of the hybrid finite element-boundary element analysis of 2D eddy current problems by means of the fast multipole method. An adaptive truncation scheme for the expansion of the 2D Laplace Green function is proposed. A linear time harmonic test case is considered. The results obtained with the hybrid model, with and without fast multipole acceleration, agree well with those obtained with a finite element model. The computational cost of the three calculations is compared and discussed. The proposed adaptive truncation scheme significantly contributes to the computation time savings achieved with the fast multipole method, particularly when dealing with moderate sized problems. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailCombined implicit/explicit time-integration algorithms for the numerical simulation of sheet metal forming
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg

in Journal of Computational & Applied Mathematics (2004), 168(1-2, Sp. Iss. SI), 331-339

In order to simulate stamping processes, an explicit method, which is conditionally stable, is generally thought to be the most adapted. Such an algorithm presents the advantage of being noniterative ... [more ▼]

In order to simulate stamping processes, an explicit method, which is conditionally stable, is generally thought to be the most adapted. Such an algorithm presents the advantage of being noniterative while, the contact configuration evolves rapidly, and the conditional stability is not a disadvantage since time steps must be small enough anyway for an accurate computation. But during the springback simulation, an implicit method, which is iterative, presents the advantage of unconditional stability. The optimal solution is then to have both implicit and explicit methods readily available in the same code and to be able to switch automatically from one to the other. Criteria that decide to switch from a method to another, depending on the current dynamic, have been developed. Implicit restarting conditions are also proposed that annihilate numerical oscillations resulting from an explicit calculation. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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