Sökning: "Wolfgang Kropp"

Hittade 3 avhandlingar innehållade orden Wolfgang Kropp.

  1. 1. Reduction of Audible Noise of a Traction Motor at PWM Operation

    Författare :Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic noise; pulse width modulation PWM ; switching frequency; traction motor; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : A dominating source for the radiated acoustic noise from a train at low speeds is the traction motor. This noise originates from electromagnetic forces acting on the structure resulting in vibrations on the surface and thus radiated noise. It is often perceived as annoying due to its tonal nature. LÄS MER

  3. 2. Effective vibro-acoustical modelling of rubber isolators

    Författare :Michael Coja; Leif Kari; Wolfgang Kropp; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; Rubber isolator; Bush mounting; Dynamic stiffness; Waveguide; Fractional derivatives; Mode-matching; Pre-compressed; Prestrain; Preload; Predeformation; Viscoelasticity; Dispersion; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : This thesis, gathering four papers, concerns the enhancement in understanding and modelling of the audible dynamic stiffness of vibration rubber isolators including experimental measurements. Paper A studies the performances of three different types of vibration isolator using an indirect measurement technique to estimate the blocked dynamic transfer stiffness of each specimen. LÄS MER

  4. 3. Vehicle Disc Brake Roughness Noise : Experimental Study of the Interior Noise andVibro-Acoustic Modelling of Suspension Systems

    Författare :Eskil Lindberg; Nils-Erik Hörlin; Peter Göransson; Wolfgang Kropp; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; disc brake; surface topography; wire brush noise; roughness noise; component mode synthesis; vehicle suspension;

    Sammanfattning : Prediction of vehicle disc brake roughness noise is a non-trivial challenge. In fact, neither the source mechanisms, nor the transfer paths are so far well understood. LÄS MER