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008			220900s2000 th uzm rtt 00| a1eng d
035			_a.b11809358
099		9	_aAIT Thesis no.ST-00-24
100	0		_aNatthapong Areemit
245	1	0	_aApplication of a pendulum-type tuned mass damper to suppress the vortex-induced oscillation of a 90-m-tall steel stack
260			_aBangkok : _bAsian Institute of Technology, _c2000
300			_a72 leaves
490	1		_aThesis ; _vno. ST-00-24
500			_aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering
502			_aThesis (M.Eng.) - Asian Institute of Technology, 2000
520			_aDuring design period, a 90-m-tall steel stack was found to have large across-wind response due to vortex resonance at low wind speed at which service life of the stack was sharply reduced. A pendulum Tuned Mass Damper (TMD) was chosen to be installed with the stack in order to provide additional damping, which is beneficial to control the response at resonance. It was designed to have a ring-shape mass in order to let it oscillates in any direction around the stack. Because the relative motion of the stack and the pendulum TMD was excessive at the optimal condition, the mass and the damping of the pendulum TMD had been increased to keep the relative motion within acceptable level without any losses in performance. To ensure that the pendulum TMD would be tuned with the stack, the parameters of the stack and the pendulum TMD were separately investigated. Geometric non-linearity of the cable and spring constant of the damper were also observed. The natural frequency, predicted by the finite element model, showed a good agreement with the measured value. It was observed that significant increases in damping level are produced by the pendulum TMD. The full-scale measurement of wind-induced responses of the stack and the pendulum TMD was set up four months after installation to monitor the performance of the pendulum TMD in service conditions. The responses of the stack had been recorded for almost two months together with wind speed and direction data. No significant reduction in the performance of the pendulum TMD in service conditions was found. The oscillation of the stack showed well defined along-wind and across-wind responses. Unfortunately, the vortex resonant response was not detected during the measurement due to very low wind speed.
650	1	0	_aBuildings _xVibration
650	1	0	_aDamping (Mechanics)
700	0		_aPennung Warnitchai, _eChairperson
700	0		_aPichai Nimityongskul, _eExamination Committee
700	1		_aZhu, Hongping, _eExamination committee
710	2		_aRoyal Thai Government, _eScholarship donor
710	2		_aHRD Phase II, _eScholarship donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. ST-00-24
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B06850
907			_a.b11809358 _bmnait _cu
902			_a240331
998			_b0 _c000922 _dm _ea _fu _g0
945			_lmnait
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942			_c22
942			_c40
909			_aBarcode : 30050120326490 _bCREATED : 2014-05-20 _cRECORD # : i12801653 _dLPATRON : 1029050 _eLCHKIN : 2018-10-08 _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 1 _iTOT CHKOUT : 6 _jTOT RENEW : 4
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