Shifting resonance and anti-resonance frequencies of rotors using frequency response functions

In this thesis, structural modification methods based on Sherman-Morrison (SM) and Sherman-Morrison-Woodbury (SMW) formulas, in which the frequency response functions (FRF) of the system are used, have been applied to rotor systems in order to obtain rotors with the desired dynamic properties. Since the FRFs of the system under investigation are used directly in these methods, there is no need for the mathematical model or modal data of the system. The FRFs to be used can be easily measured experimentally on the real model and used for structural modification. In this respect, it can be said that it provides convenience compared to many other structural modification methods and is quite suitable for practical applications. In this context, structural modification methods based on SM and SMW formulas are presented to be applied to rotor systems. It has been demonstrated by various numerical simulation studies and experimental applications that both direct and inverse structural modification studies can be performed effectively in rotors with the presented methods. Rotor finite element (FE) models created using Matlab were used for simulation studies. In the simulation studies, some mass and stiffness modifications to be made in the rotor systems within the scope of direct structural modifications and how the dynamic properties of the system change in different boundary conditions have been tried to be determined. At the same time, mass and stiffness modifications that have to be made in the coordinates determined on the rotor systems in order to obtain the desired dynamic properties within the scope of inverse structural modifications were tried to be calculated. In addition to mass and stiffness modifications in rotor systems, it has been shown that structural modifications can be made by using disk-like elements. The use of disk-like elements in structural modification applications is important in terms of making structural modifications in both translational and rotational coordinates. Also, it has been shown that anti-resonance frequencies in rotor systems can be shifted to desired values by making similar structural modifications. Anti-resonance frequencies are important in solving many vibration problems, in terms of creating vibration-insensitive points.