國立虎尾科技大學 |

Effects of turbulent wind on nonlinear response of slender structures.

紀錄類型:	書目-語言資料,手稿 : Monograph/item
正題名/作者:	Effects of turbulent wind on nonlinear response of slender structures./
作者:	Awad, Mohammed K.
面頁冊數:	1 online resource (212 pages)
附註:	Source: Dissertation Abstracts International, Volume: 76-01(E), Section: B.
Contained By:	Dissertation Abstracts International76-01B(E).
標題:	Civil engineering. -
電子資源:	click for full text (PQDT)
ISBN:	9781321173727

Effects of turbulent wind on nonlinear response of slender structures.
Awad, Mohammed K.

Effects of turbulent wind on nonlinear response of slender structures. - 1 online resource (212 pages)

Source: Dissertation Abstracts International, Volume: 76-01(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

The design of tall slender structures is fundamentally rooted in the vibration induced by lateral forces. In particular, the forces due to ambient wind, resulting from in-line buffeting to across-wind-induced vibration (primarily due to vortex shedding) have become critical factors in the design and control of tall slender structures. Over the last few decades, engineers and researchers have used conceptual understanding based on formulations and experimental studies and generated techniques to control building vibration, and thus design procedures.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781321173727Subjects--Topical Terms:

561339
Civil engineering.
Index Terms--Genre/Form:

554714
Electronic books.

Effects of turbulent wind on nonlinear response of slender structures.
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099 $a TUL $f hyy $c available through World Wide Web
100 1 $a Awad, Mohammed K. $3 1184266
245 1 0 $a Effects of turbulent wind on nonlinear response of slender structures.
264 0 $c 2014
300 $a 1 online resource (212 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertation Abstracts International, Volume: 76-01(E), Section: B.
500 $a Adviser: Khondokar Y. Billah.
502 $a Thesis (Ph.D.) $c Stevens Institute of Technology $d 2014.
504 $a Includes bibliographical references
520 $a The design of tall slender structures is fundamentally rooted in the vibration induced by lateral forces. In particular, the forces due to ambient wind, resulting from in-line buffeting to across-wind-induced vibration (primarily due to vortex shedding) have become critical factors in the design and control of tall slender structures. Over the last few decades, engineers and researchers have used conceptual understanding based on formulations and experimental studies and generated techniques to control building vibration, and thus design procedures.
520 $a One important aspect of engineering problem that is still not that well-developed is the effect of turbulence on vortex-induced vibration -- and, this is quite crucial, since almost always wind is turbulent and not steady. To date, empirical models for vortex-induced vibration under laminar flow have been supplemented by stochastic process of the turbulent wind. However, in the in state-of-the-art research, assumption is made, that the fluctuation due to wind turbulence is a white noise stochastic process. This not only causes physical inconsistencies but formulation difficulties as well, since the dynamic pressure induced by wind is proportional to the square of fluctuation.
520 $a The present work first posits that the assumption of the fluctuation as a white noise should be avoided, and the real-world of correlated noise should be used. However, as is well-known, this assumption also means that the standardized method of solving structural vibration response using stochastic differential equations with uncorrelated noise -- which is pretty well-developed - cannot be used for the vibration of real-world structures.
520 $a To get realistic time response of structures under colored noise, numerical method must be used. To that end, in this work, first, a physically-consistent model of vortex-induced vibration for the first mode is expressed as a coupled system for the slender structures, with proper understanding of the terms that produce excitation of the structures. The turbulence is then superimposed over the multiplicative term of vortex excitation. The work, thus, delves on the generation of the wind force: Spectral Method is used, via FFT technique, to generate realistic wind-turbulence using realistic power-spectral density of narrow banded, as well as exponential noise.
520 $a In order to study the response of structure to turbulent wind, the coupled second order nonlinear differential equations, involving nonlinear mode coupling forms the basis. Corresponding to the generated wind force, structural response is calculated in terms of mean square displacement. Although the coupled system is the main focus, a simplification - for practical reason - is also implemented by assuming the large-scale vortex-induced vibration to be essentially period. Two types of formulations are thus used, as a cross-check, involving both two and one degree of freedom system.
520 $a The response of structure is numerically calculated using the nonlinear differential equation, using the classical fourth order Runge-Kutta method. The response calculations performed using different parameter values - both for the wind turbulence and structural parameters - shows the effect of each parameters in the structural response. For the different parameters, the responses have a whole gamut of range, and thus only realistic parameters of physical structures are used. In the large, the responses are dependent upon the effect of turbulence, and it verifies the important aspect of intermittent response, as has been experimentally observed. This obtained result give credence to the present modelling process, as compared to the existing ones using white noise process. Based on this fundamental feature the responses were calculated for varying parameters such as structural damping, strength of vortex-shedding, spread of the narrow-band turbulence etc., and it shows realistic consistencies to experimental observations. In addition, based on the experience acquired through this effort, innovative future work is suggested for further contribution to this important field of structural engineering.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Civil engineering. $3 561339
650 4 $a Architectural engineering. $3 1180400
655 7 $a Electronic books. $2 local $3 554714
690 $a 0543
690 $a 0462
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Stevens Institute of Technology. $b Schaefer School of Engineering & Science. $3 1184267
773 0 $t Dissertation Abstracts International $g 76-01B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3635976 $z click for full text (PQDT)