Model updating of a helicopter structure using a newly developed correlation improvement technique

Altunel, Fatih
Numerical model usage has substantially increased in many industries. It is the aerospace industry that numerical models play possibly the most important role for development of optimum design. However, numerical models need experimental verification. This experimental verification is used not only for validation, but also updating numerical model parameters. Verified and updated models are used to analyze a vast amount of cases that structure is anticipated to face in real life. In this thesis, structural finite element model updating of a utility helicopter fuselage was performed as a case study. Initially, experimental modal analyses were performed using modal shakers. Modal analysis of test results was carried out using LMS Test.lab software. At the same time, finite element analysis of the helicopter fuselage was performed by MSC.Patran & Nastran software. v Initial updating was processed first for the whole helicopter fuselage then, tail of the helicopter was tried to be updated. Furthermore, a new method was proposed for the optimum node removal location for getting better Modal Assurance Criterion (MAC) matrix. This routine was tried on the helicopter case study and it showed better performance than the Coordinate Modal Assurance Criterion (coMAC) that is often used in such analyses.


Development of a bidding algorithm used in an agent-based shop-floor control system
Uluer, Muhtar Ural; Kılıç, Sadık Engin; Department of Mechanical Engineering (2007)
In this study a time based bidding framework is developed which is used for dispatching jobs to manufacturing resources in a virtual shop-floor environment. Agent-based shop-floor control approach is implemented with machine and part agents. The Contract-net communication protocol is utilized as the negotiation scheme between these agents. Single step product reservation (SSPR) technique is adopted throughout the study. Primary objective is determined as meeting the due dates and if the lateness is inevitab...
Optimum Profile Modifications for the Minimization of Dynamic Transmission Error
ÖZTÜRK, VEYSEL YALIN; Ciğeroğlu, Ender; Özgüven, Hasan Nevzat (2014-08-28)
An optimization study is performed target being the reduction of dynamic transmission error (DTE) for a selected operational range, where the operating torque and speed ranges are defined. For this purpose, two different models, i.e. a single degree of freedom (SDOF) lumped gear dynamics model and a multi-degree of freedom (MDOF) lumped model of a gear pair which is combined with shaft and bearing dynamics are employed. The differences between the optimization results obtained through loaded static transmis...
Simulation of flexible manufacturing systems: a pilot implementation
Yücel, Necati Deniz; Kılıç, Sadık Engin; Department of Mechanical Engineering (2005)
Manufacturing industry has made extensive use of simulation as a means of trying to model the impact of variability on manufacturing system behavior and to explore various ways of coping with change and uncertainty. Simulation helps find optimal solutions to a number of problems at both design and application stages of Flexible Manufacturing Systems (FMS̕s) serving to improve the أflexibilityؤ level The flexibility requirement of FMS necessitates the dissemination of every activity that concerns production,...
Design improvements on mixed flow pumps by means of computational fluid dynamics
Özgen, Onur; Albayrak, Kahraman; Department of Mechanical Engineering (2006)
The demand on high efficiency pumps leads the manufacturers to develop new design and manufacturing techniques for rotodynamic pumps. Computational Fluid Dynamics (CFD) software are started to be used during the design periods for this reason in order to validate the designs before the pumps are produced. However the integration process of CFD software into the design procedure should be made carefully in order to improve the designs. In this thesis, the CFD software is aimed to be integrated into the pump ...
Assessment of sheet metal forming processes by numerical experiments
Önder, İ. Erkan; Tekkaya, A. Erman; Department of Mechanical Engineering (2005)
Sheet metal forming technologies are challenged especially by the improvements in the automotive industry in the last decades. To fulfill the customer expectations, safety requirements and market competitions, new production technologies have been implemented. This study focuses on the assessment of conventional and new sheet metal forming technologies by performing a systematic analysis. A geometry spectrum consisting of six different circular, elliptic, quad cross-sections are selected for the assessment ...
Citation Formats
F. Altunel, “Model updating of a helicopter structure using a newly developed correlation improvement technique,” M.S. - Master of Science, Middle East Technical University, 2009.