Development of an advanced composite external fuel tank for air platforms

Karahan, Uğurcan
This thesis provides a design approach for an external fuel tank, which permits external mounting to the air platforms including rotorcrafts and aircrafts. The development stages include both a computational and an experimental study. In this thesis, unique combination of advanced composite material solutions is investigated in the structural design process. Filament-wound tank structure is modeled as multi-layered orthotropic structure. Various worst-case loading scenarios defined by internationally recognized design standards and regulations are performed by utilizing a software platform based on Finite Element Method (FEM). Results obtained by means of FEM are examined in order to determine a proper winding angle and to verify the performance of the structure exposed to combined static and transient loadings in the operating environment of the structure. The insight gained by means of such analyses allows examining every structural aspect of the tank structure. The failure prediction is performed according to the Reserve Factor index calculated for Tsai-Wu Failure Theory. The dynamic response of the structure during a crash is determined with a full-scaled prototype of the External Fuel Tank. The most severe conditions that the tank would experience when deployed within the entire operational envelope are simulated at the first non-destructive sled test facility of Turkey which is the Vehicle Safety Facility of METU-BILTIR. The result of the simulation indicates that the survival of the tank structure is ensured during severe crash impact conditions. Finally, this study has resulted in obtaining an External Fuel Tank, which maintains its structural integrity for all loading conditions, while meeting the weight target.


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Citation Formats
U. Karahan, “Development of an advanced composite external fuel tank for air platforms,” M.S. - Master of Science, Middle East Technical University, 2014.