Search results for "Numerical analysi"

An alternative space-time meshless method for solving transient heat transfer problems with high discontinuous moving sources

2016

International audience; The aim of this work is the development of a space-time diffuse approximation meshless method (DAM) to solve heat equations containing discontinuous sources. This work is devoted to transient heat transfer problems with static and moving heat sources applied on a metallic plate and whose power presents temporal discontinuities. The space-time DAM using classical weight function is convenient for continuous transient heat transfer. Nevertheless, for problems including discontinuities, some spurious oscillations for the temperature field occur. A new weight function, respecting the principle of causality, is used to eradicate the physically unexpected oscillations.

in Informatique graphique, modélisation géométrique et animation

2007

International audience; no abstract

Kernel Density Estimation applied to the chance-constrained Goddard problem

2016

Optimisation d’un lanceur

2015

A nonlinear derivative

2014

International audience; A nonlinear derivative is directly defined in the discrete domain. This derivative is motivated by the asymmetry of pattern in discrete signal as step or edge in 2D signal. Thanks to the special definition (in the discrete domain) of this derivative, pattern can be detected in a univocal way. This derivative is the only one able to perfectly detect and localize ideal edges in image. Beside this fundamental benefit, the derivative has the nice property to reduce noise. Ap- plications to edge detection, noise reduction and noise estimation are described and their performances are studied.

Fonctions d’itérations vectorielles, itérations rationnelles

1995

International audience

Recherches d’extréma par des méthodes d’extrapolation

1994

International audience

Méthodes de lagrangien et de Nitsche pour l'approximation numérique des conditions de contact avec frottement

2021

L'objectif de ce chapitre est de faire une présentation détaillée de développements récents sur l'approximation des conditions de contact des solides déformables en petites et grandes déformations. Les principes de base des méthodes de lagrangien, lagrangien augmenté, lagrangien stabilisé, de pénalité et de Nitsche sont exposés. Les liens étroits existants entre la méthode de Nitsche, le lagrangien stabilisé et le lagrangien augmenté sont alors analysés.

On the analytical expression of the multicompacton and some exact compact solutions of a nonlinear diffusive Burgers’type equation

2018

International audience; We consider the nonlinear diffusive Burgers' equation as a model equation for signals propagation on the nonlinear electrical transmission line with intersite nonlinearities. By applying the extend sine-cosine method and using an appropriate modification of the Double-Exp function method, we successfully derived on one hand the exact analytical solutions of two types of solitary waves with strictly finite extension or compact support: kinks and pulses, and on the other hand the exact solution for two interacting pulse solitary waves with compact support. These analytical results indicate that the speed of the pulse compactons doesn't depends explicitly on the pulse a…

A few remarks about the computer implementation and the verification of some hyperelastic constitutive laws and an illustration with the mechanical r…

2022

In this short technical note, we are interested in the constitutive equations used to model macroscopically the mechanical function of soft tissues under mechanical loading. Soft tissues have the ability to undergo large elastic reversible deformations under quasi-static loading and are usually modelled using hyperelastic constitutive laws. Several constitutive equations have been defined in the literature by means of strain components or strain invariants isotropic hyperelastic models. This short technical note recalls how to derive the weak form for hyperelasticity equations, and how this weak form can be linearized. It also presents a semi-analytical solution for a simplified geometry re…