Search for dissertations about: "Fractional derivatives"

Showing result 1 - 5 of 9 swedish dissertations containing the words Fractional derivatives.

2. 1. Modelling Stiffness and Damping by Use of Fractional Calculus with Application to Railpads

   Author : Åsa Fenander; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Modelling damping by use of fractional derivatives

   Author : Åsa Fenander; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : .... READ MORE

5. 3. Fractional Calculus and Linear Viscoelasticity in Structural Dynamics

   Author : Mikael Enelund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; linear viscoelasticity; convolution integrals; anisotropy; structural modeling; finite elements; material damping; time integration; internal variables; relaxation; fractional calculus; creep; Mittag-Leffler functions;

   Abstract : The use of linear viscoelasticity together with fractional calculus in time-domain structural modeling is studied. Both constitutive and structural aspects are investigated. READ MORE

6. 4. Hybrid and Dynamic Substructuring Methods for Energy Flow Analysis

   Author : Anders Wilson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fractional derivatives; structural modeling; mid-frequency; finite element method FEM; vibro-acoustics; statistical energy analysis SEA; dynamic substructuring; hybrid analysis; viscoelasticity;

   Abstract : Modeling techniques and solution tools to analyze the dynamic and vibro-acoustic behavior of complex built-up structures are matters of increasing interest, especially for thin walled structures as in transportation vehicles, such as automobiles, trucks, trains and aircraft. In structures like these, the reduction of cost, weight, sound and vibration levels are primary issues for research and development. 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