Publications associées à A projected super-penalty method for the C1-coupling of multi-patch isogeometric Kirchhoff plates

Adaptive isogeometric methods with C-1 (truncated) hierarchical splines on planar multi-patch domains

Isogeometric analysis is a powerful paradigm which exploits the high smoothness of splines for the numerical solution of high order partial differential equations. However, the tensor-product structure of standard multivariate B-spline models is not well s ...

WORLD SCIENTIFIC PUBL CO PTE LTD2023

Application of optimal spline subspaces for the removal of spurious outliers in isogeometric discretizations

Espen Sande

We show that isogeometric Galerkin discretizations of eigenvalue problems related to the Laplace operator subject to any standard type of homogeneous boundary conditions have no outliers in certain optimal spline subspaces. Roughly speaking, these optimal ...

2022

Tree-cotree decomposition of isogeometric mortared spaces in H(curl) on multi-patch domains

Rafael Vazquez Hernandez, Bernard Kapidani

When applying isogeometric analysis to engineering problems, one often deals with multi-patch spline spaces that have incompatible discretisations, e.g. in the case of moving objects. In such cases mortaring has been shown to be advantageous. This contribu ...

2022

Accurate isogeometric methods for trimmed shell structures

Luca Coradello

Shell elements derived from the Kirchhoff-Love theory have experienced a renaissance in the Finite Element community since the advent of isogeometric analysis. Despite numerous promising advancements in the field, several questions need to be addressed to ...

EPFL2021

Isogeometric analysis with C1 hierarchical functions on planar two-patch geometries

Rafael Vazquez Hernandez

Adaptive isogeometric methods for the solution of partial diifferential equations rely on the construction of locally refinable spline spaces. A simple and efficient way to obtain these spaces is to apply the multi-level construction of hierarchical spline ...

2020

Hierarchically refined isogeometric analysis of trimmed shells

Davide D'Angella, Luca Coradello, Alessandro Reali

This work focuses on the study of several computational challenges arising when trimmed surfaces are directly employed for the isogeometric analysis of Kirchhoff-Love shells. To cope with these issues and to resolve mechanical and/or geometrical features o ...

SPRINGER2020

Isogeometric Mortar Coupling for Electromagnetic Problems

Annalisa Buffa, Rafael Vazquez Hernandez

This paper discusses and analyzes two domain decomposition approaches for electromagnetic problems that allow the combination of domains discretized by either Nédélec-type polynomial finite elements or spline-based isogeometric analysis. The first approach ...

2020

Explicit dynamic approach for unbounded domains in frictional contact with Rate and State laws

Jean-François Molinari, Roozbeh Rezakhani

The paper explores the ability of an explicit time integration procedure to simulate the dynamics of shear rupture between unbounded elastic blocks on frictional interface, modeled with the finite element method. The behaviour of the interface is governed ...

ELSEVIER2020

A priori error for unilateral contact problems with Lagrange multipliers and isogeometric analysis

Annalisa Buffa, Mathieu Jonathan Fabre, Pablo Antolin Sanchez

In this paper, we consider unilateral contact problem without friction between a rigid body and deformable one in the framework of isogeometric analysis. We present the theoretical analysis of the mixed problem. For the displacement, we use the pushforward ...

2019

Coupling non-conforming discretizations of PDEs by spectral approximation of the Lagrange multiplier space

Simone Deparis, Luca Pegolotti, Antonio Iubatti

This work focuses on the development of a non-conforming method for the coupling of PDEs based on weakly imposed transmission conditions: the continuity of the global solution is enforced by a finite number of Lagrange multipliers defined over the interfac ...

2019

Volumetric untrimming: Precise decomposition of trimmed trivariates into tensor products

Pablo Antolin Sanchez

3D objects, modeled using Computer Aided Geometric Design (CAGD) tools, are traditionally represented using a boundary representation (B-rep), and typically use spline functions to parameterize these boundary surfaces. However, recent development in physic ...

2019

A finite element framework based on bivariate simplex splines on triangle configurations

Juan Cao, Xiaodong Wei

Recently, triangle configuration based bivariate simplex splines (referred to as TCB-spline) have been introduced to the geometric computing community. TCB-splines retain many attractive theoretic properties of classical B-splines, such as partition of uni ...

ELSEVIER SCIENCE SA2019

A saddle point approach to an optimal boundary control problem for steady Navier-Stokes equations

Alfio Quarteroni, Andrea Manzoni

In this paper we propose a saddle point approach to solve boundary control problems for the steady Navier-Stokes equations with mixed Dirichlet-Neumann boundary conditions, both in two and three dimensions. We provide a comprehensive theoretical framework ...

2019

Refinement Algorithms for Adaptive Isogeometric Methods with Hierarchical Splines

Rafael Vazquez Hernandez

The construction of suitable mesh configurations for spline models that provide local refinement capabilities is one of the fundamental components for the analysis and development of adaptive isogeometric methods. We investigate the design and implementati ...

2018

An isogeometric boundary element method for electromagnetic scattering with compatible B-spline discretizations

Rafael Vazquez Hernandez

We outline the construction of compatible B-splines on 3D surfaces that satisfy the continuity requirements for electromagnetic scattering analysis with the boundary element method (method of moments). Our approach makes use of Non-Uniform Rational B-splin ...

2018

Optimal Lagrange Multipliers for Dependent Rate Allocation in Video Coding

Pascal Frossard, Ana Karina De Abreu Goes

In a typical video rate allocation problem, the objective is to optimally distribute a source rate budget among a set of (in)dependently coded data units to minimize the total distortion. Conventional Lagrangian approaches convert the lone rate constraint ...

Elsevier2018

Compactly-Supported Smooth Interpolators for Shape Modeling with Varying Resolution

Michaël Unser, Daniel Andreas Schmitter, Julien René Pierre Fageot, Pablo Garcia-Amorena Garcia, Anaïs Laure Marie-Thérèse Badoual

In applications that involve interactive curve and surface modeling, the intuitive manipulation of shapes is crucial. For instance, user interaction is facilitated if a geometrical object can be manipulated through control points that interpolate the shape ...

2017

Isogeometric Analysis of high order Partial Differential Equations on surfaces

Alfio Quarteroni, Luca Dede', Andrea Bartezzaghi

We consider the numerical approximation of high order Partial Differential Equations (PDEs) defined on surfaces in the three dimensional space, with particular emphasis on closed surfaces. We consider computational domains that can be represented by B-spli ...

Elsevier2015

Optimized Coding Strategies for Interactive Multiview Video

Ana Karina De Abreu Goes

The natural next step in improving the realistic experience in multimedia services is interactive multiview video (IMV). IMV promises to enable the users to freely navigate through a scene by selecting their preferred viewpoints from any view position for ...

EPFL2015

Finite Dimensional Methods for Differential Flatness

Basile Graf

In Control System Theory, the study of continuous-time, finite dimensional, underdetermined systems of ordinary differential equations is an important topic. Classification of systems in different categories is a natural initial step to the analysis of a g ...

EPFL2013