Sökning: "complex modulus"

Visar resultat 1 - 5 av 72 avhandlingar innehållade orden complex modulus.

1. 1. Estimation of state and identification of complex modulus based on measurements om a bar traversed by waves

   Författare :Lars Hillström; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Wave; extensional; flexural; bar; rod; beam; elastic; viscoelastic; complex modulus; non-parametric; parametric; standard deviation; Materialvetenskap; Materials science; Teknisk materialvetenskap; Solid Mechanics; hållfasthetslära;

   Sammanfattning : Estimation of state and identification of complex modulus based on measurements on non-uniform rods and beams have been studied theoretically and experimentally. Two principal cases were studied. In the first case, the material properties are fully known and the state at a section is to be estimated. LÄS MER

3. 2. Identification of Viscoelastic Materials by Use of Wave Propagation Methods

   Författare :Saed Mousavi; Bengt Lundberg; Urmas Valdek; Janne Färm; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; Identification; Viscoelastic; Complex modulus; Complex Poisson s ratio; wave; Impact; Teknisk fysik; Engineering physics; Teknisk fysik;

   Sammanfattning : Complex moduli and Poisson’s ratio have been estimated using extensional and torsional wave experiments. The data were used for assessment of linearity and isotropy of two polymers, polymethyl methacrylate (PMMA) and polypropylene (PP). The responses of both materials were found to be close to linear and isotropic. LÄS MER

4. 3. Electrostatic Interactions in Complex Liquids : A Thermodynamic Analysis Based on the Poisson-Boltzmann Equation and the Flexible Surface Model

   Författare :Ingemar Carlsson; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AOT; AerosolOT; ionic surfactant; spontaneous curvature; bending modulus; bending energy; Helfrich curvature energy; fluid membrane; complex liquid; flexible surface model; micelle; counterion; Poisson-Boltzmann equation; cell model; L3 phase; sponge phas; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : The aim of this study was to analyse physico-chemical properties of some complex liquids using the Poisson-Boltzmann (PB) cell model; to extend the theory to cover bilayer systems with complex global geometry; finally to apply this new extended model to such bilayer systems. The PB cell model provides a practical tool to examine counterion association and phase behaviour for structures of simple geometries; cylindrical and spherical. LÄS MER

5. 4. Two problems of viscoelastic impact : prediction of impact force and identification of complex modulus

   Författare :Sven Ödeen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : .... LÄS MER

7. 5. Viscoelastic Materials : Identification and Experiment Design

   Författare :Agnes Rensfelt; Torsten Söderström; Händel Peter; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; viscoelastic materials; complex modulus; system identification; optimal experiment design; distributed parameter systems; frequency domain identification; wave propagation; Automatic control; Reglerteknik; Elektroteknik med inriktning mot reglerteknik; Electrical Engineering with specialization in Automatic Control;

   Sammanfattning : Viscoelastic materials can today be found in a wide range of practical applications. In order to make efficient use of these materials in construction, it is of importance to know how they behave when subjected to dynamic load. LÄS MER