Publications associées à Comparing the Buckling Strength of Spherical Shells With Dimpled Versus Bumpy Defects

Instabilities in Elastic and Magneto-Elastic Beams and Shells: from Shell Buckling to the Design of a Programmable Braille Reader

In this thesis, we conduct a comprehensive investigation into structural instabilities of both elastic and magneto-elastic beams and shells, resulting in a creative proposal to design a programmable braille reader. Methodologically, we combine numerical si ...

EPFL2024

Geometric Learning: Leveraging differential geometry for learning and control

Bernardo Fichera

In this thesis, we concentrate on advancing high-level behavioral control policies for robotic systems within the framework of Dynamical Systems (DS). Throughout the course of this research, a unifying thread weaving through diverse fields emerges, and tha ...

EPFL2024

Short-term behavior of glass fiber-polymer composite bending-active elastica beam under service load application

Thomas Keller, Landolf-Giosef-Anastasios Rhode-Barbarigos, Tara Habibi

Bending-active elastica beam is a structural configuration that is based on the elastic deformation of an initially straight beam. This deformation occurs when horizontal displacements are applied to a sliding support, causing the beam to bend into an arch ...

2024

Postbuckling behavior and imperfection sensitivity of elastic-plastic periodic plate-lattice materials

Fani Derveni

Advances in additive manufacturing have enabled a new generation of materials with advantageous properties inherent to their architecture. Recently, architected materials with periodic arrangements of plates, called plate-lattice materials, have been devel ...

ELSEVIER2022

Conjugate heat transfer in isolated granular clusters with interstitial fluid using lattice Boltzmann method

Mehrdad Kiani Oshtorjani

The conjugate heat transfer in mixtures of a fluid and single granular clusters is studied in this paper using a novel lattice Boltzmann method (LBM) programmed for parallel computation on the graphics processing unit (GPU). The LBM is validated for heat c ...

PERGAMON-ELSEVIER SCIENCE LTD2022

RADCAM-A radiation camera system combining foil bolometers, AXUV diodes, and filtered soft x-ray diodes

Basil Duval, Umar Sheikh, Luke Simons

Measurements of radiated power are critical for characterizing and optimizing tokamak performance. The RADCAM system, comprising arrays of foil bolometers, Absolute eXtreme UltraViolet (AXUV), and filtered soft x-ray diodes, has been constructed to provide ...

2022

Stabilized isogeometric discretizations on trimmed and union geometries, and weak imposition of the boundary conditions for the Darcy flow

Riccardo Puppi

Modern manufacturing engineering is based on a ``design-through-analysis'' workflow. According to this paradigm, a prototype is first designed with Computer-aided-design (CAD) software and then finalized by simulating its physical behavior, which usually i ...

EPFL2022

Strengthening mechanisms in dilute and random solid solution high-entropy BCC alloys

Alireza Ghafarollahi

Tuning the mechanical properties of metals, including strength, through adjusting the type and/or concentration of added solute elements, has been recognized as an effective way to design and produce materials with desired or optimized mechanical propertie ...

EPFL2022

Overlapping Multipatch Isogeometric Method With Minimal Stabilization

Annalisa Buffa, Pablo Antolin Sanchez, Riccardo Puppi, Xiaodong Wei

We present a novel method for isogeometric analysis (IGA) to directly work on geometries constructed by Boolean operations including difference (i.e., trimming), union, and intersection. Particularly, this work focuses on the union operation, which involve ...

SIAM PUBLICATIONS2021

Reduced-order Models for Simulating Coupled Geometric Instabilities in Steel Beam-columns Under Inelastic Cyclic Straining

Alexander Riley Hartloper

Numerical models that can simulate coupled geometric instabilities in steel beam-columns are required for the seismic assessment of certain steel moment-resisting frames. Reliably simulating coupled instabilities requires that the steel material is precise ...

EPFL2021

Magneto-active elastic shells with tunable buckling strength

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla, Dong Yan, Arefeh Abbasi

Shell buckling is central in many biological structures and advanced functional materials, even if, traditionally, this elastic instability has been regarded as a catastrophic phenomenon to be avoided for engineering structures. Either way, predicting crit ...

Nature Research2021

Soft functional fibers for mechanical sensing and actuation

Andreas Leber

The measurement and generation of mechanical deformations is a key functionality in health monitoring, human-machine interaction, and soft robotics. However, current methods typically rely on small and hard transducers, which result in poor performance, cu ...

EPFL2021

The influence of the kinematics of rough surface engagement on the transfer of forces in cracked concrete

Miguel Fernández Ruiz

One of the most instrumental aspects governing the response of structural concrete at ultimate limit state refers to the possibility of developing smeared cracking patterns within a member (associated normally to the presence of sufficient reinforcement fo ...

2021

Buckling of pressurized spherical shells containing a through-thickness defect

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla, Dong Yan

We present a study on the pressure buckling of thin, elastic spherical shells containing a thickness defect. Methodologically, we combine precision model experiments, finite element simulations, and a reduced axisymmetric shell model. We observe qualitativ ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Influence of Load Duration on Shear Strength of Reinforced Concrete Members

Aurelio Muttoni, Miguel Fernández Ruiz, Darko Tasevski

The significance of sustained loading on the compressive and tensile strength of concrete has been experimentally verified since the 1950s and is currently acknowledged in most design codes implicitly or explicitly. However; its influence on other potentia ...

AMER CONCRETE INST2020

Mechanical Characterization of Integrally-Attached Timber Plate Structures: Experimental studies and macro modeling technique

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Spurred by the recent advancements in Computer-Aided Design (CAD), Integral Mechanical Attachment (IMA) technique has been resurrected. Using IMAs, connections between timber elements are established through their form, instead of using additional connecto ...

EPFL2020

A Gauss-Bonnet Theorem for Asymptotically Conical Manifolds and Manifolds with Conical Singularities

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The purpose of this thesis is to provide an intrinsic proof of a Gauss-Bonnet-Chern formula for complete Riemannian manifolds with finitely many conical singularities and asymptotically conical ends. A geometric invariant is associated to the link of both ...

EPFL2019

A Learned Shape-Adaptive Subsurface Scattering Model

Wenzel Alban Jakob, Delio Aleardo Vicini

Subsurface scattering, in which light refracts into a translucent material to interact with its interior, is the dominant mode of light transport in many types of organic materials. Accounting for this phenomenon is thus crucial for visual realism, but exp ...

ASSOC COMPUTING MACHINERY2019

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

On Establishing Buckling Knockdowns for Imperfection-Sensitive Shell Structures

Emmanuel Georges Albert Virot

This paper investigates issues that have arisen in recent efforts to revise long-standing knockdown factors for elastic shell buckling, which are widely regarded as being overly conservative for well-constructed shells. In particular, this paper focuses on ...

ASME2018