02078nam a2200253   450000500170000000800410001703500150005810000180007324500660009126000520015730000100020949000270021950001450024650200580039152010030044965000450145265000240149770000370152170000480155870000450160671000490165181000590170085600650175920260818085720.0220798         th                  eng    a.b101809900 aBui Thanh Tam10aDamping identification of structure using free vibration data  aBangkok :bAsian Institute of Technology,c1991  a55 p.1 aThesis ;vno. ST-91-01  aA thesis submitted in partial fulfillment of the requirements  for the degree of Master of Engineering, School of Engineering and Technology  aThesis (M.Eng.) - Asian Institute of Technology, 1991  aQuantification of damping is by far the most vexing problem in dynamics of structures,  because damping does not refer to a unique physical phenomenon. The ability to estimate damping  ratios accurately plays an important role in the design of dynamically sensitive structures.  A modern method of system identification, the Ibrahim Time Domain method, is applied to  estimate the modal characters of structure. The effect of the white noise on the accuracy of identifying  natural frequency and damping ratio is investigate through numerical examples : Single degree of  freedom system, three degree of freedom system, and structure with a tuned mass damper (TMD).  The results confirm that the accuracy of the solution depends on the number and characteristics of  data series, on the number of data points, on the sampling period, on the closeness of natural  frequencies, and on the magnitude of damping. The study also shows the advantages of the method  over the logarithmic decrement method. 0aStructural dynamicsxStatistical methods 0aDamping (Mechanics)1 aYamaguchi, Hiroki, eChairperson1 aKarasudhi, Pisidhi, eExamination Committee1 aMaekawa, Koichi, eExamination Committee2 aGovernment of Australia, eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. ST-91-01  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B17694