Search for dissertations about: "Audible"

Showing result 1 - 5 of 46 swedish dissertations containing the word Audible.

2. 1. Magneto-sensitive rubber in the audible frequency range

   Author : Peter Blom; Leif Kari; Luigi Bregant; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magneto-sensitivity; Rubber; Audible frequency range; Amplitude dependence; Vibration isolator; Fletcher-Gent effect; Stiffness; Acoustics; Akustik;

   Abstract : The dynamic behaviour in the audible frequency range of magneto-sensitive (MS) rubber is the focus of this thesis consisting of five papers A-E. Paper A presents results drawn from experiments on samples subjected to different constant shear strains over varying frequencies and magnetic fields. READ MORE

4. 2. On dynamic properties of rubber isolators

   Author : Mattias Sjöberg; KTH; []
   Keywords : Rubber isolator; Dynamic stiffness; Nonlinear; Payne effect; Audible frequency; Fractional derivative; Mittag-Leffler function; Thermo-rheologically simple; Neo-Hooke;

   Abstract : This work aims at enhancing the understanding and to provideimproved models of the dynamic behavior of rubber vibrationisolators which are widely used in mechanical systems.Initially, a time domainmodel relating compressions tocomponent forces accounting for preload effects, frequency anddynamic amplitude dependence is presented. READ MORE

5. 3. Reduction of Audible Noise of a Traction Motor at PWM Operation

   Author : Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 4. Modelling and simulation of electromagnetic audible noise generated by traction motors

   Author : Fredrik Botling; Ines Lopez Arteaga; Siv Leth; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vibro-acoustics; Electromagnetic noise; traction motor; modal analysis; multi-physics; Vehicle and Maritime Engineering; Farkostteknik;

   Abstract : An annoying tonal noise is produced by modern electrical trains duringacceleration and deceleration. This noise is caused by electromagneticforces generating structural vibrations, especially from the traction motors. READ MORE

7. 5. Effective vibro-acoustical modelling of rubber isolators

   Author : Michael Coja; Leif Kari; Wolfgang Kropp; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE