Active vibration control of a smart sandwich plate via piezoelectric sensors and actuators

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Havacılık ve Uzay Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: YUNUS TANSU AKSOY

Danışman: MELİN ŞAHİN

Özet:

In this study, the first three vibration modes of a smart sandwich plate, which are 1st out-of-plane bending, 1st torsion and 2nd out-of-plane bending modes, are aimed to be suppressed by using active vibration control techniques comprising a pole placement controller. Smart sandwich plate is composed of a passive sandwich composite plate and piezoelectric patches (PZT Lead-Zirconate-Titanate) attached with epoxy adhesive at specific locations determined by using finite element modelling and analysis. Those PZT patches on the smart sandwich plate are then used both as actuators and sensors. Before manufacturing the smart sandwich plate, the locations of PZT patches are determined by considering the vibrational characteristics of the sandwich plate. Following this, an experimental modal analysis is performed to verify the finite element analysis results. Additionally, the model is updated according to the experimental results. Then, an algorithm is adapted in order to determine the spatial locations of the PZT patches and parallel to the obtained results they are attached to the passive sandwich plate. After the manufacturing process of the smart sandwich plate, a system identification is performed experimentally by sending an input signal covering the frequencies of interest and recording the response through a designated sensor. Having obtained the frequency response function of the smart sandwich plate experimentally, a transfer function is fitted in the frequency domain. Finally, various active vibration controllers are designed. Those controllers are then validated through simulations and applied in an experimental environment via pole placement method combined with various observers and filters to suppress the free and forced vibrations of the smart sandwich plate at the aforementioned resonance frequencies. The three different designed controllers are observed to suppress the vibrations in each of the aimed mode successfully by working individually and also operating together without compromising the individual performance of the controllers in the vibration suppression of the smart sandwich plate.