Investigation of fatigue behaviour of external stores under fixed wing aircraft platforms during random vibration

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Tezin Türü: Yüksek Lisans

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

Tezin Onay Tarihi: 2015

Öğrenci: EMRE OKUR

Danışman: SERKAN DAĞ

Özet:

In this study, fatigue behaviour of an external store during captive carriage at the underwing and wingtip of a fixed wing aircraft platform is investigated. The F-16C jet aircraft was determined as a fixed wing aircraft platform in this thesis which is commonly used by Turkish Army. As the external store, a data measurement store (DMS) was designed to measure loads during captive carrage. While the DMS was being attached to the F-16C jet aircraft, it flew in 5 different sorties. Acceleration and strain data were collected during these sorties. Accelerometers were used to generate power specral densities (PSD) for the vibration tests and fatigue analyses. Strain gages were placed to the most critical locations for fatigue calculations. For fatigue calculations, annual flight of F-16C jet aircraft was taken into consideration. From this annual flight data, an ideal average sortie for F-16C jet aircraft (IASF-16JA) was generated. Acceleration and strain data collected from 5 different sorties were separated and picked according to this ideal average F-16C jet aircraft sortie. For data processing and analyses Matlab, MS Excel, Ncode, MSC – Patran ve MSC – Nastran were used. Strain data were used for fatigue calculations and acceleration vi data were used to generate captive carriage vibration profiles. Also, using these vibration profiles a sample fatigue analysis was done. Moreover, reduction and determination of the vibration test duration was explanied.