Sökning: "contact modeling"

Visar resultat 6 - 10 av 139 avhandlingar innehållade orden contact modeling.

  1. 6. On multiscale modeling of pearlitic steel

    Författare :Erik Lindfeldt; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cementite; crystal plasticity; Pearlite; multiscale modeling; computational homogenization; digital image correlation; ferrite; in-situ SEM;

    Sammanfattning : By studying pearlitic steels using a scanning electron microscope it can be observed that pearlite is a two-phase material with cementite lamellae embedded in a matrix of ferrite. The cementite is commonly described as being stiff and brittle in comparison to the ferrite which is considered to have a soft and ductile mechanical behavior. LÄS MER

  3. 7. Mechanical modeling of granite subjected to contact loading

    Författare :Hossein Shariati; Per-Lennart Larsson; Francois Hild; Mahdi Saadati; Timo Saksala; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid Mechanics; Hållfasthetslära;

    Sammanfattning : The mechanical properties of Bohus granite subjected to contact loading is investigated based on experimental and numerical results. An elasto-plastic constitutive material model combined with a damage description is employed. The material model parameters are determined based on experimental results. LÄS MER

  4. 8. EMC in railway systems : measurements, modeling and analysis

    Författare :Stefan Niska; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance;

    Sammanfattning : The subject of this study and resulting thesis was to investigate the electromagnetic compatibility (EMC) problems in the multi-electrical signaling circuitry along a railway track. These signaling systems have been expanding over time from buried multi-wired electrical copper cables to optical fiber cables, sometimes located parallel to the contact line in the catenaries. LÄS MER

  5. 9. Modeling and characterization of novel MOS devices

    Författare :Stefan Persson; KTH; []
    Nyckelord :MOSFET; SiGe; high-k dielectric; metal gate; mobility; charge sheet model; retrograde channel structure; intrinsic charge; intrinsic capacitance; contact resistivity;

    Sammanfattning : Challenges with integrating high-κ gate dielectric,retrograde Si1-xGexchannel and silicided contacts in future CMOStechnologies are investigated experimentally and theoreticallyin this thesis. ρMOSFETs with either Si or strained Si1-xGex surface-channel and different high-κgate dielectric are examined. LÄS MER

  7. 10. Beam-to-Beam Contact and Its Application to Micromechanical Simulation of Fiber Networks

    Författare :Hamid Reza Motamedian; Artem Kulachenko; Umberto Perego; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber network; beam-to-beam contact; rotational contact; non-consistent; simulation; finite element; multiscale; microscale; micromechanics; paper; refining; beating; fine; hygroexpansion; shrinkage; drying; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : This doctoral thesis covers the topic of modeling the three-dimensional fiber net- works with the finite element method. It contains the part addressing the numerical aspects of the modeling, namely, the contact formulation and application of the developed methods to the fundamental questions such as the effect of randomness in fiber properties and effect of fines and hygroexpansion. LÄS MER