Sökning: "damping devices"

Visar resultat 1 - 5 av 42 avhandlingar innehållade orden damping devices.

  1. 1. Vibration mitigation of high-speed railway bridges : Application of damping devices in theory and practice

    Författare :Sarah Tell; Raid Karoumi; Andreas Andersson; Ülker-Kaustell Mahir; José Maria Goicolea; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration mitigation; high-speed railway bridges; damping devices; retrofit; numerical analysis; hybrid simulation; field experiment; vibrationsdämpning; järnvägsbroar för höghastighetståg; dämpare; eftermonteringsmetod; numerisk analys; hybridsimulering; fältförsök; Structural Engineering and Bridges; Bro- och stålbyggnad;

    Sammanfattning : The dynamic response of railway bridges is an important aspect to consider, as the repetitive loading from passing trains may result in excessive vibrations of the bridge deck. Several design criteria are developed in order to assure the structural safety and passenger comfort during train crossings of a bridge. LÄS MER

  3. 2. Piezoelectric Generation and Damping of Extensional Waves in Bars

    Författare :Anders Jansson; Bengt Lundberg; Urmas Valdek; Peter Olsson; Uppsala universitet; []
    Nyckelord :Technology; Piezoelectric; wave; generation; damping; bar; TEKNIKVETENSKAP;

    Sammanfattning : This thesis focuses on the electromechanical processes of generation and damping of transient waves in bars with attached piezoelectric members. In particular, the influence of amplifier and electrical circuitry on the mechanical waves is of interest. LÄS MER

  4. 3. Modeling and Verification of Ultra-Fast Electro-Mechanical Actuators for HVDC Breakers

    Författare :Ara Bissal; Göran Engdahl; Elena Lomonova; KTH; []
    Nyckelord :Actuators; Armature; Capacitors; Circuit breakers; Coils; Damping; Eddy currents; Elasticity; Electro-mechanical devices; Electromagnetic forces; Finite element methods; HVDC transmission; Image motion analysis; Magnetic domains; Magnetic flux; Magnetic forces; Magnetic materials; Magnets; Thermal analysis; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. LÄS MER

  5. 4. Impact damping and airplane towing : two studies of the response of solid bodies to transient loads

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

    Sammanfattning : The impact of a linearly elastic hammer on a linearly viscoelastic plate is the first problem considered in this thesis. The results, obtained by using the Laplace transformation method, can be used in the design of impact protection devices. LÄS MER

  7. 5. Enhanced Active Resonant DC Circuit Breakers for HVDC Grids

    Författare :Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active damping; Actuator; DC circuit breakers; DC grid; DC power systems; Fast mechanical switch; Fault handling strategy; Gas discharge devices; HVDC; HVDC circuit breakers; Multilevel converters; Multiterminal HVDC; Power transmission; Spark gaps; Thomson-coil actuator; Vacuum interrupter; Voltage Source Converter VSC ; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : High-voltage DC (HVDC) grids are considered promising for the electricity grid expansion required to integrate renewable energy sources into the existing infrastructure. DC fault currents increase rapidly and lack a current zero crossing. LÄS MER