Sökning: "Leif Kari"

Visar resultat 6 - 10 av 27 avhandlingar innehållade orden Leif Kari.

1. 6. Magneto-sensitive elastomers in vibration isolation

   Författare :Ane Alberdi-Muniain; Leif Kari; N Gil-Negrete; Luigi Bregant; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Järnvägsgruppen - Effektiva tågsystem för godstrafik; Järnvägsgruppen - Effektiva tågsystem för godstrafik;

   Sammanfattning : Vibration isolators made of rubber are used in numerous engineeringapplications to isolate structures from undesirable effects of vibrations.However, once a vibration isolator is installed in an application, it is not possible to modify its characteristics to adjust to changing conditions. LÄS MER

3. 7. Novel Technique to Improve High-Velocity Cold Compaction : Processing of Polymer Powders and Polymer-Based Nanocomposite High Performance Components

   Författare :Bruska Azhdar; Bengt Stenberg; Leif Kari; Mikael Rigdahl; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer powders; nanocomposites; high-velocity compaction; high-energy ball milling; Manufacturing engineering; Produktionsteknik;

   Sammanfattning : Compaction of polymer powders and polymer-based nanocomposites by uniaxial high-velocity cold compaction (HVC), by high-energy ball milling (HEBM) and using a novel technique, relaxation assists, was investigated with a focus on the process parameters, the compactibility characteristics, surface morphology and friction. The basic phenomena associated with HVC are explained and the general energy principle is introduced to explain the pull-out phenomenon, springback gradient, delay time, relative time of the pressure wave, and stick-slip phenomenon during the compaction process. LÄS MER

4. 8. Development of new techniques for the numerical modelling of railway track dynamics. Application to rolling noise assessment

   Författare :Blas Blanco; Leif Kari; Ernesto García-Vadillo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Track modelling; Timoshenko element; local deformation; distributed supports; moving Green s functions; rolling noise;

   Sammanfattning : The numerical modelling is widely employed for the prediction of the railway track dynamic behaviour, which is of utmost importance for the characterisation of the undesired medium-high frequency phenomena, such as corrugation, wheel-out-of-roundness and noise emission. This study is devoted to the improvement of railway track numerical modelling, the efficient resolution of the problem in the time domain and the assessment of rolling noise for different approaches of the track modelling. LÄS MER

5. 9. Railway track dynamic modelling

   Författare :Blas Blanco; Leif Kari; Stefano Bruni; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Track modelling; Timoshenko element; local deformation; response discontinuity; distributed supports; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The railway vehicles are an increasing mean of transportation due to, its reduced impact on environment and high level of comfort provided. These reasons have contributed to settle a positive perception of railway traffic into the European society. LÄS MER

7. 10. Exploring the vibration control potential of magneto-sensitive rubber

   Författare :Peter Blom; Leif Kari; James Busfield; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; magneto-sensitive rubber; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

   Sammanfattning : Two new aspects of the dynamic behaviour in the audible frequency range of magneto-sensitive (MS) rubber are highlighted: the existence of an amplitude dependence of the shear modulus—referred to as the Fletcher–Gent effect—for even small displacements, and the appearance of large MS effects. These results have been obtained experimentally and are subsequently used to model two examples of magneto-sensitive rubber isolators to show how by means of MS rubber they can be improved. LÄS MER