Publications related to On Establishing Buckling Knockdowns for Imperfection-Sensitive Shell Structures

Proliferation-driven mechanical compression induces signalling centre formation during mammalian organ development

Localized sources of morphogens, called signalling centres, play a fundamental role in coordinating tissue growth and cell fate specification during organogenesis. However, how these signalling centres are established in tissues during embryonic developmen ...

Nature Portfolio2024

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

Pedro Miguel Nunes Pereira de Almeida Reis, Arefeh Abbasi, Fani Derveni

We investigate the effect of defect geometry in dictating the sensitivity of the critical buckling conditions of spherical shells under external pressure loading. Specifically, we perform a comparative study between shells containing dimpled (inward) versu ...

ASME2023

A diamond spin qubit scanning probe microscope

Dinesh Kevin Mathais Pinto

The properties of a physical system only exist in relation to its environment. This thesis presents the development of a novel spin qubit scanning probe microscope operating over a wide range of environmental conditions. The qubit, which sits at the heart ...

EPFL2023

Non-destructive Prediction of the Buckling Load of Cylindrical Shells

Emilio José Lozano Vazquez

The current research focuses on the prediction of the maximum axial compression load a cylindrical shell is able to bear. This maximum axial compression load is the value at which a cylindrical shell loses stability and abruptly buckles. After the buckling ...

EPFL2022

Probing the buckling of pressurized spherical shells

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

The prediction of the critical buckling conditions of shell structures is plagued by imperfection sensitivity. Non-destructive testing through point-load probing has been recently proposed to map the stability landscape of cylindrical shells. However, the ...

2021

Scale limitations of gas bearing supported turbocompressors for vapor compression cycles

Jürg Alexander Schiffmann

An analysis of single-stage centrifugal compressors supported on dynamic, gas lubricated bearings for driving vapor compression cycles suggests that the maximum feasible compressor power is limited, primarily by the bearing load capacity, in the range from ...

2020

Buckling of geometrically confined shells

Matteo Pezzulla

We study the periodic buckling patterns that emerge when elastic shells are subjected to geometric confinement. Residual swelling provides access to range of shapes (saddles, rolled sheets, cylinders, and spherical sections) which vary in their extrinsic a ...

ROYAL SOC CHEMISTRY2019

Performance Assessment of Double-Layered Timber Plate Shells using Alternative Structural Systems

Yves Weinand, Anh Chi Nguyen, Petras Vestartas, Bertrand Mathieu C Himmer

With recent advances in digital fabrication, innovative wood-wood connections inspired by ancient timber joining techniques have recently been applied to various free-form timber plate structures. This paper focuses on the recently developed double-layered ...

International Centre for Numerical Methods in Engineering (CIMNE)2019

A novel microfabrication platform for hybrid multilayer MEMS

Nahid Hosseini

In Atomic force microscopy (AFM), the tip-sample interaction force can be measured through two primary detection techniques: optical beam detection (OBD) and electrical (self-sensing) readout. Compared to the optical method, the convenience of the self-sen ...

EPFL2019

Simulating Local Buckling-Induced Softening in Steel Members Using an Equivalent Nonlocal Material Model in Displacement-Based Fiber Elements

Dimitrios Lignos

Fiber-based elements are commonly used to simulate steel beam-columns because of their ability to capture P-M interactions and spread of plasticity. However, when mechanisms such as local buckling result in effective softening at the fiber scale, conventio ...

2018

A mechanical model for failures in shear of members without transverse reinforcement based on development of a critical shear crack

Aurelio Muttoni, Miguel Fernández Ruiz, Francesco Cavagnis

In this paper, a mechanical model consistent with the main assumptions of the Critical Shear Crack Theory (CSCT) is proposed for shear design of slender concrete members without shear reinforcement. To that aim, the shear force that can be transferred thro ...

2018

Effect of a collar on subsidence and local micromotion of cementless femoral stems: in vitro comparative study based on micro-computerised tomography

Dominique Pioletti, Alexandre Terrier, Valérie Hélène Emilie Malfroy Camine

Purpose The aim of this study is to quantitatively compare the difference in primary stability between collarless and collared versions of the same femoral stem. Specifically, we tested differences in subsidence and micromotion. Methods Collarless and coll ...

2018

Full-Scale Cyclic Testing of Deep Slender Wide-Flange Steel Beam-Columns under Unidirectional and Bidirectional Lateral Drift Demands

Dimitrios Lignos, Ahmed Mohamed Ahmed Elkady

Deep and slender wide-flange steel beam-columns are commonly used in steel special moment frames (SMFs) in North America. These sections provide large moment-of-inertia required to satisfy the design code’s drift limits while keeping the column steel weigh ...

International Association of Earthquake Engineering2017

Shear in reinforced concrete without transverse reinforcement : from refined experimental measurements to mechanical models

Francesco Cavagnis

Since the first applications of structural concrete, the shear behaviour of one-way slabs without transverse reinforcement has been largely investigated. Nevertheless, currently in the scientific community there is no general agreement on the mechanisms of ...

EPFL2017

Musculoskeletal Model of the Human Shoulder for Joint Force Estimation

David Ingram

Human beings like all organisms, are subject to a variety of diseases. Musculoskeletal diseases such as arthritis, that affect our muscles and bones, are particularly debilitating in that they considerably limit our ability to interact with our environment ...

EPFL2015

Miniature active damping stage for scanning probe applications in ultra high vacuum

Klaus Kern, Maximilian Assig, Carola Strasser

Scanning probe microscope (SPM) experiments demand a low vibration level to minimize the external influence on the measured signal. We present a miniature six-degree of freedom active damping stage based on a Gough-Stewart platform (hexapod) which is posit ...

2012

Fire Performance of Water-Cooled GFRP Columns. Part II: Postfire Investigation

Thomas Keller, Yu Bai

The postfire mechanical performances of water-cooled full-scale GFRP cellular columns subjected to axial compression were evaluated after exposure to an ISO-834 fire from one side for periods of 60 and 120 mins. The elastic modulus and postfire buckling lo ...

American Society of Civil Engineers2011

Stretching and Breaking of Ultrathin MoS2

Andras Kis, Jacopo Brivio, Simone Bertolazzi

We report on measurements of the stiffness and breaking strength of monolayer MoS2, a new semiconducting analogue of graphene. Single and bilayer MoS2 is exfoliated from bulk and transferred to a substrate containing an array of microfabricated circular ho ...

2011

Fire endurance performance of cellular GFRP columns with water-cooling system

Thomas Keller, Yu Bai, Christian Ludwig

Experimental results on the fire endurance of full-scale glass fiber-reinforced polymer (GFRP) composite columns are reported in this paper. The pultruded four-cell profiles were first loaded to axial compression (uniform serviceability stress of 5 MPa) an ...

DEStech Publications Inc.2010

A nano-tensile testing system for studying nanostructures inside an electron microscope : design, characterization and application

Dongfeng Zhang

Mechanical properties of nanostructures could be remarkably different from their bulk counterparts owing to scale effects, which have attracted considerable research interest in recent years. However, nanomechanics studies are hindered by the difficulties ...

EPFL2010