Sökning: "effect of damping"

Visar resultat 1 - 5 av 107 avhandlingar innehållade orden effect of damping.

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. On modally distributed damping in heavy vehicles

   Författare :Peter Holen; Annika Stensson Trigell; Zbigniew Lozia; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; damping; modal damping; chassis suspension; heavy vehicle; attachment compliance; Physics; Fysik;

   Sammanfattning : This thesis investigates passive damping system performance in heavy vehicles through analytical expressions, simulations with different vehicle models as well as through experimental evaluation in a tractor semi trailer combination. The objective is to study what levels of chassis suspension damping that are desirable for different vehicle modes and how this may be achieved with passive damping systems. LÄS MER

4. 3. The effects of damping treatment on the sound transmission loss of honeycomb panels

   Författare :Sathish Kumar Ramanathan; Leping Feng; Alexander Peiffer; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sandwich Structures; Honeycomb Panels; Sound Transmission; Loss Factor; Damping; Sound Radiation; Acoustics; Akustik;

   Sammanfattning : In the industry, all passenger vehicles are treated with damping materials to reduce structure-borne sound. Though these damping materials are effective to attenuate structure-borne sound, they have little or no effect on the air-borne sound transmission. LÄS MER

5. 4. Ferromagnetic Resonance as a Probe of Magnetization Dynamics : A Study of FeCo Thin Films and Trilayers

   Författare :Yajun Wei; Peter Svedlindh; Sujeet Chaudhary; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ferromagnetic resonance FMR ; Gilbert damping; magnetic coupling; FeCo;

   Sammanfattning : The high frequency dynamic magnetic responses of FeCo thin films and structures have been investigated mainly using ferromagnetic resonance (FMR) technique.The FMR resonance condition and linewidth are first derived from the dynamic Landau- Lifshitz-Gilbert equation, followed by a study of the conversion between FMR field and frequency linewidths. LÄS MER

7. 5. Electromagnetic Analysis of Hydroelectric Generators

   Författare :Martin Ranlöf; Urban Lundin; Georg Traxler-Samek; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Contra-rotating rotors; damping torque; damper winding; finite element method; hydroelectric generators; permeance model; pole shoe shape; rotational losses; single machine infinite bus; slot ripple; synchronizing torque; synchronous machines; voltage waveform.; Engineering physics; Teknisk fysik; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Hydropower maintains its position as the most important source of renewable electric energy in the world. The efficiency of large hydropower plants is unsurpassed, and after more than hundred years of development, the technology is mature and highly reliable. LÄS MER