Robustness Analysis of Intentional Mistuning Patterns in Randomly Mistuned Bladed Disk Assemblies

It is known that bladed disks, which are usually designed as cyclically symmetric structures, undergo considerable amount of forced response amplitude magnification due to the phenomenon called mistuning. Mistuning is inevitable for any cyclically symmetric bladed disk assembly since it is caused by manufacturing tolerances, material properties and operational wear. Since reducing the level of mistuning beyond certain limits is not possible with the current technology, the attempts are rather made to reduce or control the forced response magnification, where intentional mistuning is an alternative., Intentional Mistuning. is to mistune a cyclically symmetric bladed disk with a pre-defined pattern. However, because of the fact that some uncontrolled variation is still unavoidable, it is vital to evaluate any intentional mistuning pattern together with a certain amount of random mistuning. The aim of this study is to statistically compare the robustness of intentional mistuning patterns such as harmonic, linear and pseudo harmonic, with different levels of random mistuning applied on top. Therefore, intentional mistuning patterns will be evaluated without disregarding the effect of uncertainties already present in the system. Two sample bladed disk models are used to gather information on model dependence. Reduced order models of the sample bladed disks are built for this study to reduce computation time. Monte Carlo simulations with selected intentional and random mistuning pairs are then performed under pre-defined excitations to compare the performance of the intentional mistuning patterns applied.
International Conference on Noise and Vibration Engineering (ISMA)/Conference of USD


Vibration Analysis of a Cracked Beam on an Elastic Foundation
Batihan, Ali Cagri; Kadıoğlu, Fevzi Suat (2016-06-01)
The transverse vibrations of cracked beams with rectangular cross sections resting on Pasternak and generalized elastic foundations are considered. Both the Euler-Bernoulli (EB) and Timoshenko beam (TB) theories are used. The open edge crack is represented as a rotational spring whose compliance is obtained by the fracture mechanics. By applying the compatibility conditions between the beam segments at the crack location and the boundary conditions, the characteristic equations are derived, from which the n...
Dynamic modeling and analysis of vibration effects on performance in optical systems
Avşar, Ahmet Levent; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2008)
In order to understand the effects of structurally induced line of sight (SILOS) jitter (vibration) and to predict its effects on optical system performance, a simple and practical vibratory model and software are developed by using discrete and finite element modeling techniques. For an existing simple optical system, discrete and FE dynamic models are constructed and they are validated by modal tests for the frequency range of interest. In order to find material properties of adhesive, which is used in op...
Tuned vibration absorber design for a supported hollow cylindrical structure
Aksoy, Tuğrul; Özgen, Gökhan Osman; Department of Mechanical Engineering (2015)
Supported hollow structural elements have a usage area in various types of structures or machines. They exhibit an oscillatory behavior under various excitations since their modal frequencies are quite low. This behavior results in vibrations which reach huge amplitudes especially at the tip of the structures. This situation may be harmful for the structural integrity of the structures and may reduce the service life. Moreover, these vibrations can distort the performance of the machines’ which involve the ...
Free flexural( or bending) vibrations analysis of doubly stiffened, composite, orthotropic base plates and panels (in aero-structural systems)
Çil, Kürşad; Yüceoğlu, Umur; Department of Aerospace Engineering (2003)
In this Thesis, the problem of the أFree Vibrations Analysis of Doubly Stiffened Composite, Orthotropic and/or Isotropic, Base Plates or Panels (with Orthotropic Stiffening Plate Strips)ؤ is investigated. The composite plate or panel system is made of an أOrthotropic and/or Isotropic Base Plateؤ stiffened or reinforced by adhesively bonded أUpper and Lower Orthotropic Stiffening Plate Stripsؤ. The plates are assumed to be the أMindlin Platesؤ connected by relatively very thin adhesive layers. The general pr...
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...
Citation Formats
M. E. Yumer, E. Ciğeroğlu, and H. N. Özgüven, “Robustness Analysis of Intentional Mistuning Patterns in Randomly Mistuned Bladed Disk Assemblies,” presented at the International Conference on Noise and Vibration Engineering (ISMA)/Conference of USD, Leuven, BELGIUM, 2010, Accessed: 00, 2020. [Online]. Available: