Publications related to Torsional vibration

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, Elias Sebastian Klauser, Florent Alexandre Boudoire, Nikola Kalentics, Nicolas Blondiaux, Lisa Salamin

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

New Sensing Technologies for Monitoring Machinery, Structures, and Manufacturing Processes

Luc Thévenaz, Yi Huang

Sensing is the fundamental technique for sensor data acquisition in monitoring the operation condition of the machinery, structures and manufacturing processes. In this paper, we briefly discuss the general idea and advances of various new sensing technolo ...

2023

Optimization of Edge Profile for Improved Anti-Resonance Quality Factor in Lithium Niobate SH0 Resonators

Luis Guillermo Villanueva Torrijo, Silvan Stettler

Thin-film lithium niobate (LNO) has been identified as a promising material platform for enabling high electromechanical coupling and low-loss piezoelectric resonators for filtering applications. In this work, the design and fabrication of fundamental shea ...

IEEE2022

Seismic Design and Behavior of Steel Braced Frame Buildings with Friction Dampers as Dissipative Floor Connectors

Martina Paronesso

Field observations and comprehensive life-cycle building assessment suggest that buildings designed according to today's seismic standards meet the life-safety requirement. However, they are prone to economic losses due to repairs in the aftermath of earth ...

EPFL2022

Optical rotating torque sensor with nano newton-meter resolution based on a hanging torsion wire

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann, Billy Nussbaumer

This article presents a novel torque measuring setup working in the nano newton-meter range. The central novelty is a long (1 meter range) thin (diameter of a few tens of micrometers) metallic wire used instead of the relatively stiff torsion zone of the s ...

euspen2021

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

Performance and Micro-Vibrations in Magnetic Bearings for Space Actuators

Guzmán Borque Gallego

The development of new space missions with novel high-performance and very sensitive payloads for Earth observation or scientific missions has imposed considerably tougher requirements in terms of the satellite's pointing accuracy and stability, and thus o ...

EPFL2021

Experimental Study of Sliding Friction Damper for High-Performance Steel Structures

Dimitrios Lignos, Martina Paronesso

Passive energy dissipation devices are widely utilized in buildings to minimize structural and non-structural damage under seismic loading. Commonly used devices include, among others, yield, viscous and friction dampers. While the use of yield dampers, su ...

Earthquake Engineering Association2020

Equivalent-Frame Modeling of Two Shaking Table Tests of Masonry Buildings Accounting for Their Out-Of-Plane Response

Katrin Beyer, Francesco Vanin, Andrea Penna

Equivalent frame models are an effective tool for the seismic assessment of existing masonry structures. Due to their simplicity, these models can be used to perform multiple nonlinear dynamic analyses, accounting explicitly for different sources of modeli ...

FRONTIERS MEDIA SA2020

Raman spectroscopy and lattice dynamics calculations of tetragonally-structured single crystal zinc phosphide (Zn3P2) nanowires

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska

Earth-abundant and low-cost semiconductors, such as zinc phosphide (Zn3P2), are promising candidates for the next generation photovoltaic applications. However, synthesis on commercially available substrates, which favors the formation of defects, and cont ...

2020

Analysis of XBAR resonance and higher order spurious modes

Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli, Victor Plessky

A suspended 400nm thin mono-crystalline ZY cut Lithium Niobate (LN) membrane with narrow interdigital electrodes (IDEs) on top having a pitch of the order of few microns excites standing shear bulk acoustic wave resonance (XBAR) within the membrane through ...

IEEE2019

Magnetic Bearing Reaction Wheel Micro-vibration Signature Prediction

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

This article presents an analytical micro-vibration model for magnetic bearing reaction wheels (MBRWs) based on a rotordynamics model combined with the active control loop. This model is validated employing a fullyactive Lorentz-type MBRW demonstrator and ...

2019

Vibration Mode of MEMS Ultrasonic Sensors on Buckled Diaphragms with Piezoelectric Resonance Frequency Modification

Paul Muralt, Kaoru Yamashita

Vibration mode and resonance frequency of piezoelectric MEMS ultrasonic sensors was investigated on buckled diaphragm structures. The buckling of the diaphragms was introduced intrinsically through residual stress control of the piezoelectric film, and ext ...

IEEE2019

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

Scattering HCl Molecules from Au(111) and Ag(111) Surfaces

Jan Daniel Geweke

In this thesis, I present an experimental molecular beam surface scattering study of dynamical processes involved when HCl molecules are scattered from Au(111) and Ag(111) surfaces. I investigated vibrational excitation, translational inelasticity and diss ...

EPFL2019

Knee Implant Loosening Detection: A Vibration Analysis Investigation

Kamiar Aminian, Arash Arami, Hossein Rouhani

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

Local activation of surface and hybrid acoustic waves in optical microwires

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Desmond Chow Ming Chia

Elastic vibrations in subwavelength structures have gained importance recently in fundamental light–matter studies and various optoacoustic applications. Existing techniques have revealed the presence of distinct acoustic resonances inside silica microwire ...

2018

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

Yuanping Xu

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

Effects of chordwise flexibility on 2D flapping foils used as an energy extraction device

Guillaume Jeanmonod

The effects of chordwise pressure- and inertia-driven deformations on the power extraction potential of a kinematically constrained oscillating thin plate that undergoes a heaving and pitching motion are investigated. 2D fully coupled fluid-structure inter ...

Academic Press Ltd- Elsevier Science Ltd2017