Publications related to NRCtech

Related publications (21)

Vibrational NDT with Under-sampled Data through Physics-informed Neural Networks

The vibrational response of solid materials and structural components is substantially governed by their mechanical and geometrical properties. Low-frequency vibrations and modal frequencies are sensitive to global geometrical deviations, while high-freque ...

2023

Damping of flexure blades based on bi-material additive manufacturing

Simon Nessim Henein, Florent Cosandier, Loïc Benoît Tissot-Daguette, Nikola Kalentics, Florent Alexandre Boudoire, Elias Sebastian Klauser

Flexure-based mechanisms have become state-of-the-art solutions for the design of high-precision mechanisms, free from friction wear, backlash, and lubrication. These properties which are necessary for applications in ultraclean or harsh environments, neve ...

2023

Novel Generalised Notch Filter for Harmonic Vibration Suppression in Magnetic Bearing Systems

Yves Perriard, Douglas Martins Araujo, Leopoldo Rossini, Guzmán Borque Gallego

Magnetic bearings represent an important alternative to conventional ball bearings for applications that require very low noise and vibrations. The absence of contact and friction between rotor and stator parts, combined with the use of active vibration co ...

2021

Vibration Suppression Through Variable Stiffness and Damping Structural Joints

Gennaro Senatore

This paper introduces a new semi-active strategy for vibration control of truss and frame structures equipped with variable stiffness and damping joints which consist of a shape memory polymer (SMP) core reinforced by an SMP-aramid composite skin. When the ...

2020

Model-based interpretation of floor vibrations for indoor occupant tracking

Ian Smith, Yves Sylvain Gilles Reuland, Slah Drira

Information regarding occupant flows inside buildings is beneficial for applications such as thermal-load control, market research and security enhancement. Existing methodologies for occupant tracking involve data-driven techniques that rely either on rad ...

2019

Is there a relationship between footstep-impact locations and measured signal characteristics?

Ian Smith, Yves Sylvain Gilles Reuland, Sai Ganesh Sarvotham Pai, Slah Drira

Building utilization can be enhanced by tracking occupants. Non-intrusive tracking of occupants using floor-vibration measurements is beneficial for many smart-building applications such as energy consumption, security enhancement, and care-giving. Also, u ...

ACM2019

Static behavior of Reinforced UHPFRC beams with thin cover depth

Eugen Brühwiler, Bartlomiej Wojciech Sawicki

Because of its high tensile strength and deformation capacity, UHPFRC (Ultra High Performance Fiber Reinforced Cementitious composite) can theoretically be used without any reinforcement bars or prestressing. However, for more economical design and for rea ...

2019

Knee Implant Loosening Detection: A Vibration Analysis Investigation

Kamiar Aminian, Hossein Rouhani, Arash Arami

Knee implant loosening is mainly caused by the weakness of the prosthesis-bone interface and is the main reason for surgical revisions. However, pre-operative diagnosis is difficult due to lack of accurate tests. In this study, we developed a vibration-bas ...

Springer Verlag2018

Research on modal vibration suppression of maglev steel strip based on phase compensator

In the process of vibration suppression of hot galvanized steel strip by using maglev technology, the flexible modal vibration control of steel strip is a challenging problem. Aiming at this problem, this paper proposes a phase compensation control algorit ...

2018

Body vibration and its transmission in alpine ski racing

Kamiar Aminian, Benedikt Fasel

The aim of the study was to quantify the vibrations occurring at the lower limbs and the trunk during alpine ski racing. Four European Cup level athletes skied each three runs on a typical giant slalom course. For each turn, power spectral density (PSD) of ...

2016

Stabilization of electrodynamic bearings with active magnetic dampers

Qingwen Cui

Electrodynamic Bearings (EDBs) are a kind of passive magnetic bearings that exploits the interaction between the induced eddy currents in a conductor and a magnetic field to provide re-storing forces. They have been regarded as an appealing alternative to ...

EPFL2016

Experimental and Numerical Assessment of the Aeroelastic Stability of Blade Pair Packages

Peter Ott, Achim Zanker

The stabilizing effect of grouping rotor blades in pairs has been assessed both, numerically and experimentally. The bending and torsion modes of a low aspect ratio high speed turbine cascade tested in the non-rotating test facility at EPFL (Ecole Polytech ...

ASME2014

Blends of oligopeptide terminal polyisobutylene or polystyrene

Véronique Michaud, Holger Frauenrath, Emmanuel Croisier, Su Liang

Various blends of polymers are disclosed, comprising oligopeptide functionalised polymers such as polyisobutylene and polystyrene. Mono-functionalised and di-functionalised polymers (each containing 0 to 5 peptide units beyond its terminal amide group) may ...

2014

Experimental Aeroelastic Investigation of Vibrating Turbine Blade Clusters

Peter Ott, Achim Zanker

The presented work consists of the presentation and discussion of unsteady experimental results of controlled vibration measurements for two single-blade and two cluster test cases subjected to the same subsonic flow conditions. The experiments were perfor ...

Lappeenranta University of Technology2013

Fluid-Structure Coupling Effects on the Dynamic Response of Pump-Turbine Guide Vanes

Steven Roth

Hydraulic pump-turbines are subject to a high periodic excitation due to the Rotor-Stator Interaction, RSI. Basically, the RSI is caused by the impeller blade passage in the wake of the guide vanes in generating mode, or upstream from the guide vanes in pu ...

EPFL2012

Adaptive Vibration Suppression System: An Iterative Control Law for a Piezoelectric Actuator Shunted by a Negative Capacitor

Tomas Sluka

An adaptive system for the suppression of vibration transmission using a single piezoelectric actuator shunted by a negative capacitance circuit is presented. It is known that by using a negative-capacitance shunt, the spring constant of a piezoelectric ac ...

Ieee-Inst Electrical Electronics Engineers Inc2012

Dynamic behavior and vibration control of a tensegrity structure

Ian Smith, Nizar Bel Hadj Ali

Tensegrities are lightweight space reticulated structures composed of cables and struts. Stability is provided by the self-stress state between tensioned and compressed elements. Tensegrity systems have in general low structural damping, leading to challen ...

Elsevier2010

Hydrodynamics of High Specific Power Pumps for Off-Design Operating Conditions

Part load operation of high energy centrifugal pumps is associated with increased vibration levels which may adversely affect the machines operational safety. The main sources of vibrations in centrifugal pumps are of hydrodynamic nature. The interaction b ...

EPFL2010

Quantum state-resolved studies of direct and precursor-mediated dissociative chemisorption of silane on Si(100)

Thanh Tung Dang

In this work, I present the results of my studies on the state-resolved reactivity of silane (SiH4) on the Si(100)-(2x1) surface. The results demonstrate a co-existence of both a direct and a precursor mediated mechanisms for the dissociative chemisorption ...

EPFL2007

Cavitation in Kármán Vortices and Flow Induced Vibrations

François Avellan, Mohamed Farhat

The shedding process of the Kármán vortices at the trailing edge of a 2D hydrofoil at high Reynolds numbers is investigated. The focus is put on the effect of the cavitation on the vortex street morphology. A direct insight is also provided on the role of ...

2006