Optimization of vibration characteristics of a radar antenna structure

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2011

Öğrenci: İSMET BARAN

Eş Danışman: ENDER CİĞEROĞLU, GÖKHAN OSMAN ÖZGEN

Özet:

Radar antenna structures especially array antennas which are integrated onto structures of aerial vehicles are subject to dynamic structural and aerodynamic loads. Due to occurrences of these dynamic loads there will be certain dynamic deformations which affect the antenna’s performance in an adverse manner. The influence of deformations and vibrations are important on array antenna structures, since they cause a change in orientation of elements of the phased array antenna which affects the gain of the antenna negatively. In this study, vibration characteristics of a particular radar antenna structure are optimized using topology and stiffener design optimization methods such that negative effects of mechanical vibrations on functional performance of radar antenna are minimized. Topology and stiffener design optimization techniques are performed separately by the use of ANSYS Finite Element (FE) software in order to modify the design of the radar antenna structure such that its critical natural frequencies in the range of 0-500 Hz are shifted out of the dominant peak sinusoid frequency range of the air platform. As a result of this, it will be possible to minimize the vibration response of the phased array elements in the frequency range of 0-500 Hz; hence better antenna performance can be achieved. In addition to this, it will also be possible to minimize the broadband random vibration response of base excitation coming from air platform.