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Visar resultat 16 - 20 av 25 avhandlingar som matchar ovanstående sökkriterier.

  1. 16. Design of soundproof panels via metamaterial concept

    Författare :Zibo Liu; Leping Feng; Romain Rumpler; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The goal of the work is to find a way to improve the sound insulation properties of different types of panels in order to meet different requirements. Inspired by the nontrivial behavior of the locally resonant acoustic metamaterials, this concept is introduced into the design of structures in order to explore the potential ways to improve the sound insulation behavior in the relevant specific frequency regions. LÄS MER

  3. 17. Structure-acoustic analysis; finite element modelling and reduction methods

    Författare :Peter Davidsson; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; hydraulics; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; low frequency range; building acoustics; lightweight structures; porous materials; modal reduction; substructuring; finite element analysis; structural acoustics; vibroacoustics; Structural dynamics;

    Sammanfattning : This thesis investigates structure-acoustic systems by use of finite element analysis. The systems studied here are limited to those that consist of an enclosed acoustic fluid cavity, which is coupled to a flexible structure and/or a porous sound absorbing material domain. LÄS MER

  4. 18. Hearing by Bone Conduction. Physical and Physiological Aspects

    Författare :Stefan Stenfelt; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Bone conduction as a phenomenon, physically and physiologically, is of vital importance in both the diagnosis of a hearing impairment and the development of bone conduction hearing aids. Understanding hearing by bone conduction is difficult, involving sound transmission by wave motion in a complex geometrical structure of layered bone covered with soft tissue and cartilage, finally received by the highly delicate cochlea. LÄS MER

  5. 19. An experimental and numerical study of an automotive cooling module

    Författare :Anders Rynell; Gunilla Efraimsson; Michael Shur; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fan installation effects; spectral decomposition; aeroacoustics; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : Heavy vehicles are major emitters of noise. Especially at idle or low vehicle speeds a large portion of the noise emanates from the fan that forces the flow through the cooling module. The aim of this work is to investigate and reveal aerodynamic and acoustic installation effects linked to the cooling package. LÄS MER

  7. 20. Wave Modelling Techniques for Medium and High Frequency Vibroacoustic Analysis Including Porous Materials

    Författare :Hao Liu; Svante Finnveden; Ines Lopez Arteaga; Mohamed Ichchou; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Numerical methods based on wave modelling are explored for the vibroacoustic analysis of wave propagation, sound transmission and interior noise in vehicles and buildings at medium and high frequencies. The presence of sound absorbing porous materials in practical engineering structures is also considered. LÄS MER