Dokuz Eylül University Graduate School of Natural and Applied Sciences Integration of Active Vibration Control Methods with Finite Element Models of Smart Structures

Active control methods can be used to eliminate undesired vibrations in engineering structures. Using piezoelectric smart structures for the active vibration control has great potential in engineering applications. In this thesis, numerical and experimental studies on active vibration control of mechanical systems and smart structures have been presented. An integrated analysis procedure has been developed for the control of structures. The closed loop control laws are incorporated into the finite element (FE) models by using ANSYS parametric design language (APDL). The proposed procedure is first tested by applying to multi degrees of freedom mechanical systems. Then, active control of free and forced vibrations of piezoelectric smart beams in different configurations is studied with this procedure. The control gains and piezoelectric actuation voltages which provide vibration control are determined by the numerical simulations. Harmonic excitation and moving load problems are considered in the forced vibration control. The active vibration suppression is achieved using strain feedback and displacement feedback Experiments have been conducted to verify the closed loop simulations. Smart beams consist of aluminum beams (450 mm x 20 mm x 1.5 mm, 1000 mm x 20 mm x 1.5 mm) surface bonded piezoelectric patches of Sensortech BM532 (25 mm x 20 mm x 1 mm) and strain gages. The natural frequencies of cantilever smart beams are found using chirp signals. Experimental results are obtained by LabVIEW programs developed in the study. It is observed that theoretical predictions are well matched with the experimental results.