Sökning: "Frequency dynamics"

Visar resultat 1 - 5 av 496 avhandlingar innehållade orden Frequency dynamics.

1. 1. Footbridge Dynamics : Human-Structure Interaction

   Författare :Emma Zäll; Raid Karoumi; Mahir Ülker-Kaustell; Andreas Andersson; Peter Van den Broeck; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamics; vibration; footbridge; pedestrian bridge; human-structure interaction; runner; running loads; simplified models; Dynamik; vibration; gångbro; människa-bro-interaktion; löpare; löparlaster; förenklade modeller; Civil and Architectural Engineering; Byggvetenskap;

   Sammanfattning : For aesthetic reasons and due to an increased demand for cost-effective and environmentally friendly civil engineering structures, there is a trend in designing light and slender structures. Consequently, many modern footbridges are susceptible to excessive vibrations caused by human-induced loads. LÄS MER

3. 2. Integration of Non-synchronous Generation - Frequency Dynamics

   Författare :Johan Björnstedt; Industriell elektroteknik och automation; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Frequency control; Frequency dynamics; Frequency response; Non-synchronous generation; Power system; Synthetic inertia; Wind power;

   Sammanfattning : Traditionally the predominant generation has been large synchronous generators providing the system inertia. Nowadays when wind power and other non-synchronously connected units displaces this synchronous generation, the system inertia is reduced. Hence higher rate of change of frequency and larger frequency deviations are expected. LÄS MER

4. 3. Dynamics and Extreme Value Problems for Moored Floating Platforms

   Författare :Yungang Liu; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasi-static; frequency-domain; extreme value; convolution; floating platform; low-frequency; time-domain; mooring cable; wave-frequency;

   Sammanfattning : This research deals with the dynamic response analyses and extreme value problems of moored floating platforms. It can be divided into three major subjects: first, the analysis of single cables and cable induced mooring damping; second, the dynamic analysis of the moored platforms, with special emphasis on the damping mechanisms and generation of the low-frequency excitation force time series; and third, the extreme wave-frequency responses and the combination of the low-frequency and wave-frequency extreme responses. LÄS MER

5. 4. On the dynamics of footbridges : A theoretical approach and a comparison between running and walking loads

   Författare :Daniel Colmenares; Raid Karoumi; Andreas Andersson; Mahir Ülker Kaustell; Pedro Museros Romero; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; footbridges; dynamics; human induced loads; human structure interaction; harmonic load; continuous beam; gångbroar; dynamik; fotgängarlast; samverkan mellan fotgängare och bro; harmonisk last; kontinuerlig balk.; Structural Engineering and Bridges; Bro- och stålbyggnad;

   Sammanfattning : The dynamic behaviour of lightweight footbridges is often susceptible to HumanInduced Loads (HILs). Generally HILs are taken into account as moving harmonicfunctions in which the loading frequency represents the step frequency of the pedestrians. LÄS MER

7. 5. Studies in Glacier Mass Balance : Measurement and its errors

   Författare :Andrew Mercer; Peter Jansson; Gunhild Rosqvist; Ian Brown; Jonathan Carrivick; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Glaciology; Mass Balance; Measurement Errors; Physical Geography; naturgeografi;

   Sammanfattning : The study of the surface mass balance of valley glaciers has a long history but one that is dogged by uncertainty and errors, and uncertainty about those errors. These problems are acknowledged by the glaciological community and have been examined and formalised in several publications. LÄS MER