Exploració per tema "Natural frequency"

Ara es mostren els items 1-9 de 9

    • A novel Σ-Δ pulsed digital oscillator (PDO) for MEMS 

      Domínguez Pumar, Manuel; Pons Nin, Joan; Ricart Campos, Jordi; Bermejo Pelayo, Agustin; Figueras Costa, Eduardo (IEEE, 2005-12)
      Article
      Accés obert
      A novel digital oscillator topology for microelectromechanical systems (MEMS) based on bandpass sigma–delta modulation is presented. Short pulses of force of the same amplitude maintain the oscillation and the associated ...

    • Closed-form equation for natural frequencies of beams under full range of axial loads modeled with a spring-mass system 

      Valle Fraga, Juan José; Fernández Martínez, Daniel; Madrenas Boadas, Jordi (2019-04-01)
      Article
      Accés obert
      A new simple closed-form equation that accurately predicts the effect of an arbitrarily large constant axial load, residual stress or temperature shift on the natural frequencies of an uniform single-span beam, with various ...

    • Design and testing of a kinetic energy harvester embedded into an oceanic drifter 

      Carandell Widmer, Matias; Toma, Daniel; Carbonell Ventura, Montserrat; Río Fernandez, Joaquín del; Gasulla Forner, Manuel (2020-02-28)
      Article
      Accés obert
      A novel Kinetic Energy Harvester (KEH) has been developed for powering oceanic undrogued drifters. It consists on a double pendulum system capable of transforming the wave oscillations into rotation on a flywheel. This ...

    • Experimental study on the influence of vibration amplitude on the fluid damping of a submerged disk 

      Moraga González, Greco Alonso; Xia, Xiang; Roig López, Sergi; Valero Ferrando, Ma. del Carmen; Valentín Ruiz, David; Egusquiza Montagut, Mònica; Zhou, Lingjiu; Egusquiza Estévez, Eduard; Presas Batlló, Alexandre (Elsevier, 2023-10)
      Article
      Accés obert
      Accurate determination of modal parameters for disk-like structures submerged in heavy fluids is a topic of interest in many fields. For instance, some type of hydraulic turbomachinery can be modelled as disk structures ...

    • Experimental validation of a kinetic energy harvester device for oceanic drifter applications 

      Carandell Widmer, Matias; Toma, Daniel; Gasulla Forner, Manuel; Río Fernandez, Joaquín del (2019)
      Comunicació de congrés
      Accés obert
      A Kinetic Energy Harvester (KEH) device under design for drifter applications has been tested at real sea conditions in a controlled area. The KEH consists on a pendulum system capable to transform the oscillations of the ...

    • Influence of non-rigid surfaces on the dynamic response of a submerged and confined disk 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2015)
      Text en actes de congrés
      Accés obert
      Determining the dynamic response of submerged and confined disk-like structures is of interest in the hydraulic turbines field. Disks present similar dynamic characteristics than hydraulic turbine runners, especially in ...

    • Influence of the hydrodynamic damping on the dynamic response of Francis turbine runners 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Jou Santacreu, Esteban; Egusquiza Estévez, Eduard (2019-10-01)
      Article
      Accés obert
      The dynamic behavior of Francis runners is of interest in the hydraulic machinery field since it is one of the most used type of hydraulic turbines for electricity generation. To evaluate the dynamic behavior of Francis ...

    • On the exctitation of a submerged disk-like structure with RSI patterns 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich (2015)
      Text en actes de congrés
      Accés restringit per acord de confidencialitat
      Determining the dynamic response of submerged and confined disk-like structures is of interest in the hydraulic turbines field. Disks present similar dynamic characteristics than hydraulic turbine runners, especially in ...

    • Robust estimation of axial loads sustained by tie-rods in historical structures using Artificial Neural Networks 

      Makoond, Nirvan Chandra; Pelà, Luca; Molins i Borrell, Climent (2022-10)
      Article
      Accés obert
      Widely used simplified analytical methods for estimating the tensile force in tie-rods are clearly not applicable when they contain significant discontinuities or irregularities. A common example for which this fact becomes ...