Sökning: "modal damping"

Visar resultat 1 - 5 av 54 avhandlingar innehållade orden modal damping.

  1. 1. On modally distributed damping in heavy vehicles

    Författare :Peter Holen; Annika Stensson Trigell; Zbigniew Lozia; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; damping; modal damping; chassis suspension; heavy vehicle; attachment compliance; Physics; Fysik;

    Sammanfattning : This thesis investigates passive damping system performance in heavy vehicles through analytical expressions, simulations with different vehicle models as well as through experimental evaluation in a tractor semi trailer combination. The objective is to study what levels of chassis suspension damping that are desirable for different vehicle modes and how this may be achieved with passive damping systems. LÄS MER

  3. 2. Structural-acoustic vibrations in wooden assemblies : Experimental modal analysis and finite element modelling

    Författare :Åsa Bolmsvik; Torbjörn Ekevik; Andreas Linderholt; Anders Brandt; Anders Ågren; Linnéuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wooden framed structure; light weight buildings; multi-storey; flanking transmission; junction; vibration distribution; impact noise; damping; elastomers; finite element analysis; experimental modal analysis; FRF; trästomme; träkonstruktion; träbyggnad; flervåningshus; EMA; FEM; flanktransmission; koppling; knutpunkt; vibrationsspridning; stomljud; stegljud; dämpning; elastomerer; finit elementmetod; experimentell modalanalys; accelerationsmätning; frekvensresponsfunktion; modalanalys;

    Sammanfattning : This doctoral thesis concerns flanking transmission in light weight, wooden multi-storey buildings within the low frequency, primarily 20-120 Hz. The overall aim is to investigate how the finite element method can contribute in the design phase to evaluate different junctions regarding flanking transmission. LÄS MER

  4. 3. Modelling Stiffness and Damping by Use of Fractional Calculus with Application to Railpads

    Författare :Åsa Fenander; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stiffness; initial conditions; modal synthesis; time integration; measurements; fractional calculus; railway tracks; fractional integrals; damping; railpads; structural dynamics; fractional derivatives; mathematical models;

    Sammanfattning : When studying the dynamic behaviour of a structure, e g a railway track, it is important for the analyst to model both stiffness and damping accurately. Mathematical models including fractional derivatives have been found to work well for many materials. Such models are linear and causal. LÄS MER

  5. 4. On experimental material damping estimation based on vibration response models and hybride modal analysis

    Författare :Mats Dalenbring; KTH; []
    Nyckelord :Constitutive isotropic material modelling; Augmented Hooke s law; Experimental damping estimation; Finite element displacement modes; Hybrid modal analysis; Experimental modal analysis; Structural vibration modelling;

    Sammanfattning : .... LÄS MER

  7. 5. Mechanical Characterization of Engineering Materials by Modal Testing

    Författare :Daniel Larsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; material variability; modal testing; non-destructive test methods; damping ratios; timber beams; plastic panels; aluminium panel; elastic constants; concrete curing; wood-based panels; solids; high-strength concrete; anisotropic materials;

    Sammanfattning : This thesis deals with the use of modal testing for establishing elastic constants of engineering materials and for indicating material variability in terms of stiffness and damping properties. The methodology using modal testing techniques, is applied to timber beams, high strength concrete prisms, wood-based panels (oriented strand board and chipboard), an aluminium alloy panel and plastic laminate panels (high-pressure laminate). LÄS MER