03538nam a2200433 4500 20260817161500.0 150798 th eng .b10053360 AIT Thesis no. ST-93-01 Arfiadi, Yoyong Active vibration control of structures by piezoelectric actuators Bangkok : Asian Institute of Technology, 1993 50 leaves Thesis ; no. ST-93-01 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering Thesis (M.Eng.) - Asian Institute of Technology, 1993 In this study the governing equation of motion for beam structure with integrated piezoelectric actuator was formulated from the virtual work principle. The resulting governing equations are expressed in the form of ordinary differential equations in modal coordinates, where the effect of the electrically-induced strain in the actuator is shown in term of modal force. In the formulation, transverse motion as well as axial motion of the beam structure were considered. A simple beam with a direct feedback control was then studied. The feedback signal is proportional to the time rate of change in the dynamic strain at the extreme fiber of the beam nearest the actuator. This feedback introduces not only active damping to every vibrational mode, but also coupling between modes; these effects were represented in terms of a non-proportional active damping matrix. Therefore, complex modal analysis is needed to compute complex modes and complex eigenfrequencies of the system. The complex eigenfrequencies are then transformed into the equivalent modal dampings and modal frequencies. It was found that the relation between modal dampings and feedback gain is not linear; the damping increases, reaches its maximum, and then decreases when the gain is monotonically increased. Such a nonlinear phenomenon can not be identified if the coupling between modes is neglected. The phenomenon also implies that there is a physical limitation on the effectiveness of the active control scheme. Structural dynamics Piezoelectric devices Pennung Warnitchai, Chairperson Aoyagi, Yukio, Examination Committee Worsak Kanok-Nukulchai, Examination Committee Slamet Rijadi Foundation Yogyakruta, Indonesia, Scholarship Donor Canadian International Development Agency, Scholarship Donor Asian Institute of Technology. Thesis ; no. ST-93-01 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B16422 .b10053360 mnait s 240409 2 951012 m a s 0 mnait mnait mnarc 20 40 Barcode : 30050003065975 CREATED : 1995-10-13 RECORD # : i10045387 LPATRON : 1017079 LCHKIN : 2005-10-25 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 1 TOT RENEW : 0 Barcode : 30050003065983 CREATED : 1995-10-13 RECORD # : i10045399 LPATRON : 1017840 LCHKIN : 2006-11-23 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 3 TOT RENEW : 0 Barcode : 30050160023817 CREATED : 2016-03-30 RECORD # : i12913418 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 1470 1470 0 0 0 0 MAIN MAIN mnait 2026-08-17 10.00 0 AIT Thesis no. ST-93-01 30050003065975 2026-08-17 16:15:00 1 2026-08-17 20 0 0 0 0 MAIN MAIN mnait 2026-08-17 10.00 0 AIT Thesis no. ST-93-01 30050003065983 2026-08-17 16:15:00 2 2026-08-17 20 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no. ST-93-01 30050160023817 2026-08-17 16:15:00 1 2026-08-17 40