טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentYuri Simanovsky
SubjectInvestigation of the behavior of damaged aluminum panel
under shear loads, reinforced by composite patches
DepartmentDepartment of Aerospace Engineering
Supervisor Professor Abramovich Haim


Abstract

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Aging metallic aircraft, manufactured in the early 70's, are still being operated around the world, subjected to new types of damage, appearing in new locations on the aircraft. In past years, the use of composites has increased for Aluminum aircraft components. Researches substantiated these repairs to be effective from durability point of view. Many studies evaluated the effect of plies application sequence, orientation sequence, effect of stress amplification factor and more. However, all studies focused on simple tensile loading.

Forward and center sections of combat aircraft fuselage contain a skin, which plays a major role in load transferring, usually due to torsion originated by fuselage bending. This research aims to study the effect of the above mentioned parameters on composite repair patch for a panel, subjected to shear loads. This research is based on new approach of finite element modeling, consisting of 2D and 3D elements merging. Corresponding, the model is parametrically analyzed for strength and buckling, as a function of patch size, overlaps, sequences and so forth. These analyses are then substantiated by a dedicated set of experiments - representative elements. Based on the test results, we evaluate the accuracy of the finite element model and validate the method of repair patch modeling.