In this study, the contact stresses in the dovetail-rim region of an aero-engine compressor disc under the action of the centrifugal forces of the blades are investigated. Dovetail-rim consists of two parts: the blade and the disc. Highly stressed areas occur at the edges of the interface of the disc and the blade during the operation. Fretting fatigue is commonly seen in dovetails, which is caused by high stress gradients. An experimental setup which is capable of performing tension test on a dovetail rim attachment is designed. Strain gauges and a 2D digital image correlation system (DIC) are used to measure the strains. Finite element (FE) models are created for comparisons. Two sets of experiments are conducted. In the first experiment, it is seen that the misalignment of the specimens causes asymmetric contact condition in the contact pairs of dovetail. Therefore, inconsistencies between the results are observed. In the second experiment, changes are made to prevent the asymmetry giving results more consistent to the finite elements analysis (FEA). However, in the first two experiments, it is seen that the system is extremely stiff, the displacements and the strains measured are small. Therefore, these measurements are highly sensitive on tolerances and imperfections.


Acoustic Fatigue and Dynamic Behavior of Composite Panels Under Acoustic Excitation
Uz, Canan; Ata, Tamer T. (2016-01-28)
Composite panels in aircraft structures are exposed to fluctuating sound pressure originating mostly from engine noise and air flow. In this paper, acoustic fatigue and dynamic response of composite panels under acoustic excitation are investigated numerically. Composite panel is simulated with finite element analysis. The panel is considered clamped at one edge, whereas the opposite edge is assumed to be free. The panel is subjected to random repeated loading generated by sound waves. The analysis estimate...
Experimental investigation of the helicopter blade tip shape effects on aerodynamic performance and tip vortex characteristics
Uluocak, Sinem; Perçin, Mustafa; Uzol, Oğuz; Department of Aerospace Engineering (2019)
This study experimentally investigates the effects of different rotor blade tip shapes on the rotor aerodynamic performance and the tip vortex characteristics in hovering flight. Force, torque and flow field measurements were performed on a 1.3 m diameter 5-bladed model rotor for four different blades: rectangular (RECT), anhedral (ANHD), tapered-swept (TAPER) and tapered-swept-anhedral (TSA). Thrust and torque measurements show that all tip modifications have a positive effect on the aerodynamic performance wh...
Experimental investigation of failure mechanism in cross-ply and fabric curved composite laminates
Çevik, Ahmet; Çöker, Demirkan; Department of Aerospace Engineering (2021-8)
Laminated curved-shape composite parts which are used in the spar and ribs in aircraft and wind turbine blades are subjected to high interlaminar tensile and shear stresses. These stresses cause delamination and subsequent reduction in load-carrying capacity. In this study, failure mechanism of cross-ply and fabric curved composite laminates under pure transverse loading are examined experimentally using an in-house designed test fixture. Stress field over the curved beam is obtained with finite element ana...
Acoustic fatigue procedure validation and application on cavity wall
Küden, Zeynep; Çalışkan, Mehmet; Department of Mechanical Engineering (2019)
Acoustic loading formed due to boundary layer fluctuation, engine efflux and separated aerodynamic flow cause vibration that may result in fatigue failure of the structure. The subject of this thesis deals with the analytical acoustic fatigue procedure composition and validation in addition to critical wall stress analysis of representative weapon bay. It is aimed to feed the design process of the projects during its preliminary stages from structural point of view. The thesis can be discussed into two sect...
Experimental investigation of pressurized concrete tunnel linings
Kalaycıoğlu, Münci Tunç; Canbay, Erdem; Department of Civil Engineering (2019)
Behaviour of pressurized tunnels are determined by the mechanical and geometrical properties of lining, mechanical properties and overburden pressure, and the quality of contact zone between rock and lining. These factors form the backbone of the designprocessoftunnelswithinternalpressure. Estimatingcrackwidthsanddamage patternsischallengingdueto thenonlinearinteractionofnaturalandartificiallayers. Inthisstudy,influenceofkeyparametersandFRP-fabric-wraprepairingmethodwere experimentally investigated. Eight spe...
Citation Formats
A. A. Akay, D. Çöker, A. Kayran, and E. Gürses, “EXPERIMENTAL STUDY AND FINITE ELEMENT ANALYSIS OF DOVETAIL ATTACHMENTS,” 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54517.