Sökning: "Teknisk mekanik"

Visar resultat 21 - 25 av 799 avhandlingar innehållade orden Teknisk mekanik.

  1. 21. Vibration Frequencies as Status Indicators for Tensegrity Structures

    Författare :Nasseradeen Ashwear; Anders Eriksson; Karl-Gunnar Olsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tensegrity; Pre-stress; Vibration; Health monitoring; Buckling; Temperature effect; Vibration health monitoring VHM; Tensegritet; Förspänning; Vibration; Hälsokontroll; Knäckning; Temperatureffekt; Vibrationsbaserad hälsokontroll; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning :  Applications of vibration structural health monitoring (VHM) techniques are increasing rapidly. This is because of the advances in sensors and instrumentation during the last decades. VHM uses the vibration properties to evaluate many civil structures during the design steps, building steps and service life. LÄS MER

  3. 22. 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

  4. 23. 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

  5. 24. Road surface classification using near infrared spectroscopy

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

    Sammanfattning : Statistics shows that most traffic accidents with fatal outcome can be related to slippery road conditions. The most hazardous road conditions are the ones that are hard for the driver to detect and that appears sudden on the road. LÄS MER

  7. 25. 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