Articles

Dynamic data-driven model reduction: adapting reduced models from incomplete data

This work presents a data-driven online adaptive model reduction approach for systems that undergo dynamic changes. Classical model reduction constructs a reduced model of a large-scale system in an offline ph...

Authors: Benjamin Peherstorfer and Karen Willcox

Numerical simulation of solid deformation driven by creeping flow using an immersed finite element method

An immersed finite element method for solid–fluid interaction is presented with application focus on highly deformable elastic bodies in a Stokes flow environment. The method is based on a global balance equat...

Authors: Thomas Rüberg and José Manuel Garcí Aznar

Efficient solvers for time-dependent problems: a review of IMEX, LATIN, PARAEXP and PARAREAL algorithms for heat-type problems with potential use of approximate exponential integrators and reduced-order models

In this paper, we introduce and comment some recent efficient solvers for time dependent partial differential or ordinary differential problems, considering both linear and nonlinear cases. Here “efficient” ma...

Authors: Florian De Vuyst

Recursive POD expansion for reaction-diffusion equation

This paper focuses on the low-dimensional representation of multivariate functions. We study a recursive POD representation, based upon the use of the power iterate algorithm to recursively expand the modes re...

Authors: M. Azaïez, F. Ben Belgacem and T. Chacón Rebollo

General treatment of essential boundary conditions in reduced order models for non-linear problems

Inhomogeneous essential boundary conditions must be carefully treated in the formulation of Reduced Order Models (ROMs) for non-linear problems. In order to investigate this issue, two methods are analysed: on...

Authors: Alejandro Cosimo, Alberto Cardona and Sergio Idelsohn

PEBL-ROM: Projection-error based local reduced-order models

Projection-based model order reduction (MOR) using local subspaces is becoming an increasingly important topic in the context of the fast simulation of complex nonlinear models. Most approaches rely on multipl...

Authors: David Amsallem and Bernard Haasdonk

A hybrid RNN-GPOD surrogate model for real-time settlement predictions in mechanised tunnelling

Realistic 3D simulations of the tunnelling process are increasingly required to investigate the interactions between machine-driven tunnel construction and the surrounding soil in order to provide reliable est...

Authors: Ba-Trung Cao, Steffen Freitag and Günther Meschke

On the use of model order reduction for simulating automated fibre placement processes

Automated fibre placement (AFP) is an incipient manufacturing process for composite structures. Despite its conceptual simplicity it involves many complexities related to the necessity of melting the thermopla...

Authors: Nicolas Bur, Pierre Joyot, Chady Ghnatios, Pierre Villon, Elías Cueto and Francisco Chinesta

Numerical study of the square-root conformation tensor formulation for confined and free-surface viscoelastic fluid flows

We present a numerical study of a stabilization method for computing confined and free-surface flows of highly elastic viscoelastic fluids. In this approach, the constitutive equation based on the conformation...

Authors: Irineu L. Palhares Junior, Cassio M. Oishi, Alexandre M. Afonso, Manuel A. Alves and Fernando T. Pinho

Robust model reduction by \(L^{1}\)-norm minimization and approximation via dictionaries: application to nonlinear hyperbolic problems

We propose a novel model reduction approach for the approximation of non linear hyperbolic equations in the scalar and the system cases. The approach relies on an offline computation of a dictionary of solutio...

Authors: Rémi Abgrall, David Amsallem and Roxana Crisovan

Modeling cell adhesion and proliferation: a cellular-automata based approach

Cell adhesion is a process that involves the interaction between the cell membrane and another surface, either a cell or a substrate. Unlike experimental tests, computer models can simulate processes and study...

Authors: J. Vivas, D. Garzón-Alvarado and M. Cerrolaza

Towards a pancreatic surgery simulator based on model order reduction

In this work a pancreatic surgery simulator is developed that provides the user with haptic feedback. The simulator is based on the use of model order reduction techniques, particularly Proper Generalized Deco...

Authors: Andrés Mena, David Bel, Icíar Alfaro, David González, Elías Cueto and Francisco Chinesta

An error estimator for real-time simulators based on model order reduction

Model order reduction is one of the most appealing choices for real-time simulation of non-linear solids. In this work a method is presented in which real time performance is achieved by means of the off-line ...

Authors: Icíar Alfaro, David González, Sergio Zlotnik, Pedro Díez, Elías Cueto and Francisco Chinesta

Extended modelling of dislocation transport-formulation and finite element implementation

In the past decade, several higher-order crystal plasticity models have been developed to properly capture size effects, dislocation pile-up and patterning. Here we consider a formulation which accounts for th...

Authors: Michael M. W. Dogge, Ron H. J. Peerlings and Marc G. D. Geers

Effect of the separated approximation of input data in the accuracy of the resulting PGD solution

The proper generalized decomposition (PGD) requires separability of the input data (e.g. physical properties, source term, boundary conditions, initial state). In many cases the input data is not expressed in ...

Authors: Sergio Zlotnik, Pedro Díez, David Gonzalez, Elías Cueto and Antonio Huerta

3D numerical models using a fluid or a solid formulation of FSW processes with a non-cylindrical pin

Friction stir welding process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are not melted. During the FSW process, the beh...

Authors: Philippe Bussetta, Narges Dialami, Michele Chiumenti, Carlos Agelet de Saracibar, Miguel Cervera, Romain Boman and Jean-Philippe Ponthot

ASTER Shell: a simple concept to significantly increase the plastic buckling strength of short cylinders subjected to combined external pressure and axial compression

This paper proposes a new type of shell, similar to a cylindrical shell, which has significantly higher buckling strength when subjected to an arbitrary combination of uniform external pressure and axial compr...

Authors: Alain Combescure and Jean-Francois Jullien

Space–time adaptive hierarchical model reduction for parabolic equations

Surrogate solutions and surrogate models for complex problems in many fields of science and engineering represent an important recent research line towards the construction of the best trade-off between modeli...

Authors: Simona Perotto and Alessandro Zilio

High order cut finite element methods for the Stokes problem

We develop a high order cut finite element method for the Stokes problem based on general inf-sup stable finite element spaces. We focus in particular on composite meshes consisting of one mesh that overlaps a...

Authors: August Johansson, Mats G. Larson and Anders Logg

On the multi-scale description of electrical conducting suspensions involving perfectly dispersed rods

Nanocomposites allow for a significant enhancement of functional properties, in particular electrical conduction. In order to optimize materials and parts, predictive models are required to evaluate particle d...

Authors: Marta Perez, Emmanuelle Abisset-Chavanne, Anais Barasinski, Francisco Chinesta, Amine Ammar and Roland Keunings

Adaptive surrogate modeling for response surface approximations with application to bayesian inference

Parameter estimation for complex models using Bayesian inference is usually a very costly process as it requires a large number of solves of the forward problem. We show here how the construction of adaptive s...

Authors: Serge Prudhomme and Corey M. Bryant

Effect of reinforcement volume fraction and orientation on a hybrid tissue engineered aortic heart valve with a tubular leaflet design

Transcatheter aortic valve implantation of fibrin-based tissue engineered heart valves with a tubular leaflet construct have been developed as an alternative to invasive traditional surgical heart valve implan...

Authors: Scott E Stapleton, Ricardo Moreira, Stefan Jockenhoevel, Petra Mela and Stefanie Reese

Analysis of the two-dimensional polydisperse liquid sprays in a laminar boundary layer flow using the similarity transformation method

In this paper we analyze the model that describes the evaporation process of multi-size (polydisperse) of fuel droplets in a laminar boundary layer flow. The spray is described using a probability density func...

Authors: Ophir Nave

The role of cell lysis and matrix deposition in tumor growth modeling

The multiphase model for tumor growth, proposed by the authors in previous works, is here enhanced. The original model includes a solid phase, the extracellular matrix (ECM) and three fluid phases: living and...

Authors: R Santagiuliana, C Stigliano, P Mascheroni, M Ferrari, P Decuzzi and B A Schrefler

Comparison between thick level set (TLS) and cohesive zone models

Two main families of methods exist to model failure of quasi-brittle structures. The first one consists on crack based models, like cohesive zone models. The second one is a continuum damage approach that lead...

Authors: Andrés Parrilla Gómez, Nicolas Moës and Claude Stolz

Proper Generalized Decomposition computational methods on a benchmark problem: introducing a new strategy based on Constitutive Relation Error minimization

First, the effectivity of classical Proper Generalized Decomposition (PGD) computational methods is analyzed on a one dimensional transient diffusion benchmark problem, with a moving load. Classical PGD method...

Authors: Pierre-Eric Allier, Ludovic Chamoin and Pierre Ladevèze

The inequality level-set approach to handle contact: membrane case

Contact mechanics involves models governed by inequality constraints. Even for the simplest contact problem, inequalities arise from the lack of information on the contact zone position. In addition to increa...

Authors: Matthieu Graveleau, Nicolas Chevaugeon and Nicolas Moës

An upwind least square formulation for free surfaces calculation of viscoplastic steady-state metal forming problems

Despite using very large parallel computers, numerical simulation of some forming processes such as multi-pass rolling, extrusion or wire drawing, need long computation time due to the very large number of tim...

Authors: Ugo Ripert, Lionel Fourment and Jean-Loup Chenot

Shock compression modeling of metallic single crystals: comparison of finite difference, steady wave, and analytical solutions

The shock response of metallic single crystals can be captured using a micro-mechanical description of the thermoelastic–viscoplastic material response; however, using a such a description within the context o...

Authors: Jeffrey T Lloyd, John D Clayton, Ryan A Austin and David L McDowell

Stabilization in relation to wavenumber in HDG methods

Simulation of wave propagation through complex media relies on proper understanding of the properties of numerical methods when the wavenumber is real and complex.

Authors: Jay Gopalakrishnan, Stéphane Lanteri, Nicole Olivares and Ronan Perrussel

Toward a 3D coupled atomistic and discrete dislocation dynamics simulation: dislocation core structures and Peierls stresses with several character angles in FCC aluminum

We present a robust method to obtain the displacement field of a dislocation core, which is one of the building blocks for the development of a direct multiscale method coupling an atomistic domain to a discre...

Authors: Jaehyun Cho, Till Junge, Jean-François Molinari and Guillaume Anciaux

Primitive chain network simulations for elongational viscosity of bidisperse polystyrene melts

In spite of the industrial significance, molecular mechanism of the strain hardening saliently observed in bidisperse polymeric liquids has not been elucidated yet. In this study, the multi-chain slip-link sim...

Authors: Keiko Takeda, Sathish K Sukumaran, Masataka Sugimoto, Kiyohito Koyama and Yuichi Masubuchi

Efficient and accurate numerical quadrature for immersed boundary methods

One question in the context of immersed boundary or fictitious domain methods is how to compute discontinuous integrands in cut elements accurately. A frequently used method is to apply a composed Gaussian qua...

Authors: László Kudela, Nils Zander, Tino Bog, Stefan Kollmannsberger and Ernst Rank

Separation of particles in non-Newtonian fluids flowing in T-shaped microchannels

The flow of suspensions through bifurcations is encountered in several applications. It is known that the partitioning of particles at a bifurcation is different from the partitioning of the suspending fluid, ...

Authors: Gaetano D’Avino, Martien A Hulsen and Pier Luca Maffettone

Parameter identification of two-time-scale nonlinear transient models

The aim of this paper is to study two-time-scale nonlinear transient models and their associated parameter identification. When it is possible to consider two well-separated time scales, and when the fast comp...

Authors: Guillaume Puel and Denis Aubry

Component-based reduced basis for parametrized symmetric eigenproblems

A component-based approach is introduced for fast and flexible solution of parameter-dependent symmetric eigenproblems.

Authors: Sylvain Vallaghé, Phuong Huynh, David J Knezevic, Loi Nguyen and Anthony T Patera

Estimation of the validity domain of hyper-reduction approximations in generalized standard elastoviscoplasticity

We propose an a posteriori estimator of the error of hyper-reduced predictions for elastoviscoplastic problems. For a given fixed mesh, this error estimator aims to forecast the validity domain in the paramete...

Authors: David Ryckelynck, Laurent Gallimard and Samuel Jules

Estimation of error in observables of coarse-grained models of atomic systems

The use of coarse-grained approximations of atomic systems is the most common methods of constructing reduced-order models in computational science. However, the issue of central importance in developing these...

Authors: John Tinsley Oden, Kathryn Farrell and Danial Faghihi

Erratum to: Weakly periodic boundary conditions for the homogenization of flow in porous media

Authors: Carl Sandström, Fredrik Larsson and Kenneth Runesson

The double absorbing boundary method for elastodynamics in homogeneous and layered media

Recently the Double Absorbing Boundary (DAB) method was introduced as a new approach for solving wave problems in unbounded domains. It has common features to each of two types of existing techniques: local hi...

Authors: Daniel Rabinovich, Dan Givoli, Jacobo Bielak and Thomas Hagstrom

Performance evaluation of vehicle front structure in crash energy management using lumped mass spring system

The design for vehicle structural crashworthiness which ensures that components of desired crash performance characteristics are used in product manufacturing essentially involves the evaluation of the energy ...

Authors: Sunday M Ofochebe, Chigbogu G Ozoegwu and Samuel O Enibe

On the variationally consistent computational homogenization of elasticity in the incompressible limit

Computational homogenization is a well-established approach in material modeling with the purpose to account for strong micro-heterogeneity in an approximate fashion without excessive computational cost. Howev...

Authors: Mikael Öhman, Kenneth Runesson and Fredrik Larsson

A new mortar formulation for modeling elastomer bedded structures with modal-analysis in 3D

It is a well-known fact that cross-laminated timber structures are sensitive to rumbling noises. These transmissions are best captured by a fully three-dimensional mathematical model. Since the discretization ...

Authors: Thomas Horger, Stefan Kollmannsberger, Felix Frischmann, Ernst Rank and Barbara Wohlmuth

Reduced yield stress for zirconium exposed to iodine: reactive force field simulation

Iodine-induced stress-corrosion cracking (ISCC), a known failure mode for nuclear fuel cladding, occurs when iodine generated during the irradiation of a nuclear fuel pellet escapes the pellet through diffusio...

Authors: Matthew L Rossi, Christopher D Taylor and Adri CT van Duin

Coupling local and non-local damage evolutions with the Thick Level Set model

The Thick Level Set model (TLS) is a recent method to delocalize local constitutive models suffering spurious localization. It has two major advantages compared to other delocalization methods. The first one i...

Authors: Nicolas Moës, Claude Stolz and Nicolas Chevaugeon

Adjoint-consistent formulations of slip models for coupled electroosmotic flow systems

Models based on the Helmholtz `slip' approximation are often used for the simulation of electroosmotic flows. The objectives of this paper are to construct adjoint-consistent formulations of such models, and t...

Authors: Vikram V Garg, Serge Prudhomme, Kris G van der Zee and Graham F Carey

Weakly periodic boundary conditions for the homogenization of flow in porous media

Seepage in porous media is modeled as a Stokes flow in an open pore system contained in a rigid, impermeable and spatially periodic matrix. By homogenization, the problem is turned into a two-scale problem con...

Authors: Carl Sandstöm, Fredrik Larsson and Kenneth Runesson

On the sensitivity of the POD technique for a parameterized quasi-nonlinear parabolic equation

In what follows, we consider the Proper Orthogonal Decomposition (POD) technique of model order reduction, for a parameterized quasi-nonlinear parabolic equation.

Authors: Nissrine Akkari, Aziz Hamdouni, Erwan Liberge and Mustapha Jazar

Treatment of nearly-singular problems with the X-FEM

In recent years, lot of research have been conducted on fictitious domain approaches in order to simplify the meshing process for computed aided analysis. The behaviour of such non-conforming methods is studie...

Authors: Grégory Legrain and Nicolas Moës

Real time simulation for computational surgery: a review

In this paper a non-exhaustive review is made on the existing literature for real-time simulation in the field of computational surgery. Many methods have been proposed so far to deal with the very astringent ...

Authors: Elías Cueto and Francisco Chinesta