Improvement of finite element model by using sine vibration test results of acommunication satellite

Çekiç, Abdulkadir
In this thesis, the vibration analysis of a communication satellite is performed,and the improvementof the finite element model by using vibration test results is presented. First, the satellite finite element model isgenerated using MSC/PATRAN and MSC/NASTRAN commercial software. With the natural frequency and frequency response analysis, the expected frequency values and response amplitudes in accelerometers arecalculated in vibration tests. The results obtained in the vibration test arecompared with the analysis results using the HYPERGRAPH commercial software and their similaritywith the modal assurance criteriacalculation,which is developed using the FORTRAN programming language. The frequency values converged to the measured values as a result of the finite element model improvement,which is performed using error sensitivity assessment at the relevant frequencies.


Numerical Modelling and Experimental Analysis of Vibratory and Acoustics Behaviours of a Special Design Squirrel-Cage Three-Phase Asynchronous Machine
Ionescu, R. M.; Negoita, A.; N'Diaye, A.; Torregrossa, D.; Djerdir, A.; Miraoui, A.; Scutaru, Gh. (2011-09-10)
The paper presents a comparison between the obtained results from testing a special design 5 kW squirrel-cage three-phase asynchronous machine and the numerical model of the same machine, simulated under the FLUX2D Finite Element Software. The aim is to validate the numerical model in the loaded and unloaded cases. The resulting model will be used for further research into the vibratory behaviour and noise of the motor. In this paper, an experimental approach is used to show the influence of load on motor v...
Free vibration characteristics of a 3d mixed formulation beam element with force-based consistent mass matrix
Soydas, Ozan; Sarıtaş, Afşin (2017-09-01)
In this analytical study, free vibration analyses of a 3d mixed formulation beam element are performed by adopting force-based consistent mass matrix that incorporates shear and rotary inertia effects. The force-based approach takes into account the actual distribution of mass of an element in the derivation of the mass matrix. Moreover, the force-based approach enables accurate determination of free vibration frequencies of members with varying geometry and material distribution without any need for specif...
Unlusoy, Levent; Şahin, Melin; Yaman, Yavuz (2012-07-04)
In this study, the detailed finite element model (FEM) of an unmanned aerial vehicle wing torque box was verified by the experimental modal testing. During the computational studies the free-free boundary conditions were used and the natural frequencies and mode-shapes of the structure were obtained by using the MSC Software. The results were then compared with the experimentally obtained resonance frequencies and mode-shapes. It was observed that the frequencies were in close agreement having an error with...
Design of a test setup for the characterization of vibration isolators
Uz, Canan; Özgen, Gökhan Osman; Ciğeroğlu, Ender; Department of Mechanical Engineering (2013)
Design of a test setup to investigate dynamic characteristics of a vibration isolator has been extensively studied over the years and international standards are regulated to explain the basis of the measurements. In this thesis, design efforts to develop a custom test setup for measuring dynamic stiffness of vibration isolators are presented. The setup is designed to conduct dynamic stiffness measurements for various static preload values and over a certain (target) frequency range. Direct Method has been ...
Investigation of rough surface scattering of electromagnetic waves using finite element method
Aşırım, Özüm Emre; Kuzuoğlu, Mustafa; Özgün, Özlem; Department of Electrical and Electronics Engineering (2013)
This thesis analyzes the problem of electromagnetic wave scattering from rough surfaces using finite element method. Concepts like mesh generation and random rough surface generation will be discussed firstly. Then the fundamental concepts of the finite element method which are the functional form of a given partial differential equation, implementation of the element coefficient matrices, and the assemblage of elements will be discussed in detail. The rough surface and the overall mesh geometry will be imp...
Citation Formats
A. Çekiç, “Improvement of finite element model by using sine vibration test results of acommunication satellite,” M.S. - Master of Science, Middle East Technical University, 2021.