In rotors supported on a squeeze-film damper (SFD) with static eccentricity, subharmonic and quasi-periodic vibrations are generated by rotor unbalance. this paper, in Jeffcott an SFD analyzed using the modified incremental harmonic balance (IHB) method. Oil film forces calculated π theory short bearing approximation. These first time domain then transformed into frequency Fourier transformatio...

Abstract Appearance of transverse cracks in rotor systems mainly affects their stiffness content. The stability such at steady-state running is usually analyzed by using the Floquet’s theory. Accordingly, instability zones rotational speeds are dominated negative content whirl response vicinity critical speeds. Consequently, an effective measure introduced here to analyze effect crack and unbal...

A variety of systems can be faithfully modeled as linear with coefficients that vary periodically with time or Linear Time-Periodic (LTP). Examples include anisotropic rotorbearing systems, wind turbines, satellite systems, etc... A number of powerful techniques have been presented in the past few decades, so that one might expect to model or control an LTP system with relative ease compared to...

Stability analysis of lateral–torsional coupled vibration is obligatory for rotating machinery, such as aero-engines. However, the state-of-the-art method may lead to stability misjudgment under different coordinate systems. The cause this has not yet been well explored. purpose paper clarify error source in a more comprehensive manner. A vertical Jeffcott rotor model including torsion built, a...

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques a...