Enhancement of quality of modal test results of an unmanned aerial vehicle wing by implementing a multi-objective genetic algorithm optimization

2017-12-01
Pedramasl, Nima
Şahin, Melin
ACAR, ERDEM
Due the fact that aircraft structures work in an environment with lots of dynamic forces, it is of vital importance to perform a dynamic analysis to understand dynamic characteristics of aircraft in that specific environment. These characteristics are usually obtained using numerical methods (finite element analysis) or experimental methods (classical modal analysis). In classical modal analysis, quality of test equipment plays a critical role in final results' accuracy and completeness. There is another important factor which is expertise of a test engineer. Test engineer uses his/her experience to find sufficient/optimum numbers, types and locations of transducers. This process sometimes would be time consuming and exhausting which results in degradation of test results quality. In this paper an algorithm is developed and implemented to find numbers, types and locations of transducers in a modal test which will make results of test more reliable. In this study, an unmanned aerial vehicle used as dummy structure to test functionality of developed algorithm. This algorithm utilized two toolboxes from MATLAB (multi-objective genetic algorithm toolbox and parallel computing toolbox) and MSC (c) NASTRAN finite element solver. A genetic algorithm based optimization is performed in which MSC (c) NASTRAN was used to calculate dynamic characteristics of UAV wing. Since this was a time and resource consuming process a parallel computing cluster is also utilized which decreased run times at least fourfold. In algorithm it was tried to find optimum numbers, types and locations of transducers which will result in minimum cost and error in test results. Error was defined as a summation of mode shape observability error, mass loading error and optimum driving point error. At the end of study optimization results are presented and validated by classical modal analysis. (C) 2017 Elsevier Masson SAS. All rights reserved.
AEROSPACE SCIENCE AND TECHNOLOGY

Suggestions

Optimization of types, numbers and locations of sensors and actuators used in modal analysis of aircraft structures using genetic algorithm
Pedramasl, Nima; Şahin, Melin; Acar, Erdem; Department of Aerospace Engineering (2017)
Aircraft structures are exposed to dynamic loads under service conditions and therefore, it is necessary to determine their dynamic characteristics. Dynamic characteristics of a structure can be determined using simulation-based methods such as finite element analysis (FEA) or test-based methods such as experimental modal analysis (EMA). In order to perform an EMA with reliable and high quality results, test equipment must be lightweight and have high accuracy. In addition, the sensors and actuators must be...
Determination of prying load on bolted connections
Atasoy, Mert; Kayran, Altan; Department of Aerospace Engineering (2012)
Analysis of aircraft structures are mainly performed by assuming that the structure behaves linearly. In linear finite element analysis, it is assumed that deformations are small, thus geometric nonlinearity can be neglected. In addition, linear analysis assumes that linear constitutive laws applicable, implying that material nonlinearity can also be neglected. One very common type of nonlinearity is associated with the boundary conditions. Contact between two deformable bodies or between a deformable and r...
Design of a test setup for altitude simulation
Aydoğdu, Ataman; Ulaş, Abdullah; Department of Mechanical Engineering (2019)
Altitude simulation testing is an important concept in missile systems, especially in terms of aerothermal ground testing and high speed air breathing engine free-jet testing. Those tests of the missile systems at supersonic speeds need High Altitude Test System (HATS) which simulates Mach number, total pressure and total temperature of the flow on the test article mounted in the test chamber by using free-jet nozzle. To start the free-jet nozzle operation which simulates high altitude conditions, test cham...
Determination of shot peening effect on fatigue behavior of AISI 4140 steel by non-destructive measurement of surface residual stresses
Çalışkan, Salim; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2018)
The fatigue performance of aircraft parts can be improved by inducing compressive residual stresses in the near-surface zone by shot-peening. The depth profile and the magnitude of residual stresses depend on the shot peening parameters. Aircraft industry requires an easy and rapid non-destructive method for determination of residual stress state to verify the achievement of the desired results of shot-peening. This study aims to determine nondestructively the residual stresses at the surface by the Magneti...
Development of a multigrid accelerated euler solver on adaptively refined two- and three-dimensional cartesian grids
Çakmak, Mehtap; Aksel, Mehmet Haluk; Department of Mechanical Engineering (2009)
Cartesian grids offer a valuable option to simulate aerodynamic flows around complex geometries such as multi-element airfoils, aircrafts, and rockets. Therefore, an adaptively-refined Cartesian grid generator and Euler solver are developed. For the mesh generation part of the algorithm, dynamic data structures are used to determine connectivity information between cells and uniform mesh is created in the domain. Marching squares and cubes algorithms are used to form interfaces of cut and split cells. Geome...
Citation Formats
N. Pedramasl, M. Şahin, and E. ACAR, “Enhancement of quality of modal test results of an unmanned aerial vehicle wing by implementing a multi-objective genetic algorithm optimization,” AEROSPACE SCIENCE AND TECHNOLOGY, pp. 447–463, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36066.