Publications by Annalisa Buffa

A theoretical analysis of mass scaling techniques

Annalisa Buffa, Yannis Dirk Voet, Espen Sande

Mass scaling is widely used in finite element models of structural dynamics for increasing the critical time step of explicit time integration methods. While the field has been flourishing over the years, it still lacks a strong theoretical basis and mostl ...

SPRINGER2025

A spline-based hexahedral mesh generator for patient-specific coronary arteries

Simone Deparis, Annalisa Buffa, Jochen Peter Hinz

This paper presents a spline-based hexahedral mesh generator for tubular geometries commonly encountered in hæmodynamics studies, in particular coronary arteries. We focus on techniques for accurately meshing vessels with stenoses and aneurysms, as well as ...

2025

MASS LUMPING AND OUTLIER REMOVAL STRATEGIES FOR COMPLEX GEOMETRIES IN ISOGEOMETRIC ANALYSIS

Annalisa Buffa, Yannis Dirk Voet, Espen Sande

Mass lumping techniques are commonly employed in explicit time integration schemes for problems in structural dynamics and both avoid solving costly linear systems with the consistent mass matrix and increase the critical time step. In isogeometric analysi ...

AMER MATHEMATICAL SOC2025

Reduced order modeling based inexact FETI-DP solver for lattice structures

Annalisa Buffa, Pablo Antolin Sanchez, Thibaut Hirschler

This paper addresses the overwhelming computational resources needed with standard numerical approaches to simulate architected materials. Those multiscale heterogeneous lattice structures gain intensive interest in conjunction with the improvement of addi ...

Wiley2024

Reduced Order Modelling of Nonaffine Problems on Parameterized NURBS Multipatch Geometries

Annalisa Buffa, Pablo Antolin Sanchez, Margarita Chasapi

This contribution explores the combined capabilities of reduced basis methods and IsoGeometric Analysis (IGA) in the context of parameterized partial differential equations. The introduction of IGA enables a unified simulation framework based on a single g ...

Springer Science and Business Media Deutschland GmbH2024

An interior penalty coupling strategy for isogeometric non-conformal Kirchhoff-Love shell patches

Annalisa Buffa, Pablo Antolin Sanchez, Giuliano Guarino

This work focuses on the coupling of trimmed shell patches using Isogeometric Analysis, based on higher continuity splines that seamlessly meet the

C^1

requirement of Kirchhoff-Love-based discretizations. Weak enforcement of coupling conditions is achiev ...

Springer2024

On the use of elliptic PDEs for the parameterisation of planar multipatch domains

Annalisa Buffa, Jochen Peter Hinz

This paper presents a parameterisation framework based on (inverted) elliptic PDEs for addressing the planar parameterisation problem of finding a valid description of the domain’s interior given no more than a spline-based description of its boundary cont ...

2024

The Immersed Boundary Conformal Method for Kirchhoff–Love and Reissner–Mindlin shells

Annalisa Buffa, Pablo Antolin Sanchez, Giuliano Guarino

This work utilizes the Immersed Boundary Conformal Method (IBCM) to analyze linear elastic Kirchhoff–Love and Reissner–Mindlin shell structures within an immersed domain framework. Immersed boundary methods involve embedding complex geometries within a bac ...

2024

An equilibrated flux a posteriori error estimator for defeaturing problems

Ondine Gabrielle Chanon, Annalisa Buffa, Rafael Vazquez Hernandez, Denise Grappein

An a posteriori error estimator based on an equilibrated flux reconstruction is proposed for defeaturing problems in the context of finite element discretizations. Defeaturing consists in the simplification of a geometry by removing features that are consi ...

2023

Can Knowledge Transfer Techniques Compensate for the Limited Myocardial Infarction Data by Leveraging Haemodynamics? An in silico Study

Emmanuel Abbé, Simone Deparis, Annalisa Buffa, Riccardo Tenderini, Ortal Yona Senouf

The goal of this work is to investigate the ability of transfer learning (TL) and multitask learning (MTL) algorithms to predict tasks related to myocardial infarction (MI) in a small-data regime, leveraging a larger dataset of haemodynamic targets. The da ...

Springer Nature2023

A mathematical theory for mass lumping and its generalization with applications to isogeometric analysis

Annalisa Buffa, Yannis Dirk Voet, Espen Sande

Explicit time integration schemes coupled with Galerkin discretizations of time-dependent partial differential equations require solving a linear system with the mass matrix at each time step. For applications in structural dynamics, the solution of the li ...

2023

DeepBND: A machine learning approach to enhance multiscale solid mechanics

Simone Deparis, Annalisa Buffa, Pablo Antolin Sanchez, Felipe Figueredo Rocha

Effective properties of materials with random heterogeneous structures are typically determined by homogenising the mechanical quantity of interest in a window of observation. The entire problem setting encompasses the solution of a local PDE and some aver ...

2023

Immersed boundary-conformal coupling of cylindrical IGA patches

Annalisa Buffa, Pablo Antolin Sanchez

In this work an Immersed-Boundary-Conformal coupling method for coupling shells is presented. The linear elastic static analysis is carried out using the Kirchhoff-Love shell model. The variational statement is discretized with an Isogeometric Analysis app ...

Association of American Publishers2023

Region Extraction in Mesh Intersection

Annalisa Buffa, Pablo Antolin Sanchez, Emiliano Cirillo

Region extraction is a very common task in both Computer Science and Engineering with several applications in object recognition and motion analysis, among others. Most of the literature focuses on regions delimited by straight lines, often in the special ...

2023

Stabilized isogeometric formulation of the Stokes problem on overlapping patches

Annalisa Buffa, Pablo Antolin Sanchez, Riccardo Puppi

We present a novel stabilized isogeometric formulation for the Stokes problem, where the geometry of interest is obtained via overlapping NURBS (non-uniform rational B-spline) patches, i.e., one patch on top of another in an arbitrary but predefined hierar ...

Elsevier Science Sa2023

A Shape Derivative Approach to Domain Simplification

Ondine Gabrielle Chanon, Annalisa Buffa, Alessandra Arrigoni, Jochen Peter Hinz

The objective of this study is to address the difficulty of simplifying the geometric model in which a differential problem is formulated, also called defeaturing, while simultaneously ensuring that the accuracy of the solution is maintained under control. ...

Elsevier Sci Ltd2023

Reduced order modelling of nonaffine problems on parameterized NURBS multipatch geometries

Annalisa Buffa, Pablo Antolin Sanchez, Margarita Chasapi

This contribution explores the combined capabilities of reduced basis methods and IsoGeometric Analysis (IGA) in the context of parameterized partial differential equations. The introduction of IGA enables a unified simulation framework based on a single g ...

2022

Mathematical Foundations of Adaptive Isogeometric Analysis

Annalisa Buffa, Rafael Vazquez Hernandez

This paper reviews the state of the art and discusses recent developments in the field of adaptive isogeometric analysis, with special focus on the mathematical theory. This includes an overview of available spline technologies for the local resolution of ...

SPRINGER2022

Adaptive analysis-aware defeaturing

Ondine Gabrielle Chanon, Annalisa Buffa, Rafael Vazquez Hernandez

Removing geometrical details from a complex domain is a classical operation in computer aided design for simulation and manufacturing. This procedure simplifies the meshing process, and it enables faster simulations with less memory requirements. But depen ...

2022

An unrefinement algorithm for planar THB-spline parameterizations

Annalisa Buffa

Unrefinement is a tool that allows to perform faster numerical simulations by controlling the level of precision in the specified area. We introduce an algorithm that creates a coarser geometry from an initial regular geometry, which is represented with re ...

ELSEVIER2022