Sökning: "Experimentell mekanik"

Visar resultat 1 - 5 av 168 avhandlingar innehållade orden Experimentell mekanik.

1. 1. Experimental investigation of snow metamorphism at near-surface layers

   Författare :Lavan Kumar Eppanapelli; Mikael Sjödahl; Johan Casselgren; Arne Instanes; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Snow metamorphism; NIR reflectance; Snow and Ice; Radiative transfer equation; Paramterization; Snow properties; Tomography; Snow microstructure; Experimentell mekanik; Experimental Mechanics;

   Sammanfattning : Snow metamorphism is a direct objective in many snow research areas, and its charac-terisation is a major challenge in areas including winter road maintenance, detection of icing on wind turbine blades, and snow quality mapping for skiing. A common effect of snow metamorphism is compaction, which can be investigated from the associated vari-ations in physical properties of snow. LÄS MER

3. 2. Pulsed laser ablation studied using digital holographic interferometry

   Författare :Eynas Amer; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimental Mechanics; Experimentell mekanik;

   Sammanfattning : Pulsed digital holographic interferometry has been used to investigate the plume and the shock wave generated in the ablation process of a Q-switched Nd-YAG (lambda= 1064 nm and pulse duration = 12 ns) laser pulse on a polycrystalline Boron Nitride (PCBN) target under atmospheric air pressure. A special set-up based on using two synchronised wavelengths from the same laser for simultaneous processing and measurement has been used. LÄS MER

4. 3. Pulsed laser ablation studied using digital holography

   Författare :Eynas Amer; Bill O’Neill; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimental Mechanics; Experimentell mekanik;

   Sammanfattning : Pulsed digital holographic interferometry has been used to study the plume and the shock wave generated in the laser ablation process on different targets under atmospheric air pressure. A pulsed Nd-YAG laser system (pulse duration 12 ns) has been used both for ablating the material (wavelength 1064 nm) and for measurement (wavelength 532 nm). LÄS MER

5. 4. Experiments and simulations on the mechanics of ice and snow

   Författare :Hassan Bahaloohoreh; Johan Casselgren; Simon Larsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experiments; Sintering force; Capillar bridge; liquid film; Discrete Element Method; Particles; Experimentell mekanik; Experimental Mechanics;

   Sammanfattning : In this study, experiments and simulations were conducted to investigate ice and snow. The ice sintering force as a function of temperature, pressing force (contact load), contact duration, and particle size during the primary stage of sintering was formulated using experimental methods along with an approximate, semi-analytic, close-form solution. LÄS MER

7. 5. Road surface characterization using near infrared spectroscopy

   Författare :Johan Casselgren; Matti Kutila; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spektroskopi; Väglagsklassificering; Friktion; Väglagskarakterisering; Experimental Mechanics; Experimentell mekanik;

   Sammanfattning : This thesis presents a technology and method for classifying and characterizing different road conditions such as dry asphalt and asphalt covered with water, ice and snow. The method uses light sources of different wavelengths to illuminate the road surface and a detector to measure the reflected light from the road surfaces, dependent on how the surface have absorbed, scattered and polarized the light it is possible to classify the road condition. LÄS MER