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As the level of complexity of modern rotating machinery grows, the need for an effective and efficient maintenance process increases as well. In the last decade, researchers all over the world have shown strong aspiration to optimize the diagnostics phase in rotating machinery. This paper highlights some of the latest research on the detection of typical faults in rotating machinery such as mass rotor imbalance, misalignment, rub and looseness, bearing and gear faults. Various techniques for condition monitoring have been researched, and in this paper, they have been classified into three groups: physics-based, data-driven, and physics-based data-driven methods. Although most of the research falls into the first two prior mentioned groups, an intent to introduce a novel method, their symbiosis, has emerged in the last few years. The great potential for future work on physics-based data-driven methods in the field of rotating machinery has been briefly discussed. [ABSTRACT FROM AUTHOR]

A reliable operation of generators is highly dependent on the electrical and mechanical integrity of stator end-winding vibration and has been a major concern in the last two decades. This paper focuses on the experience in hammer impact testing of end-winding vibrations of parallel phase leads and series loop caps in two hydro generators in a different temperature state. The measurements were conducted using hammer testing on the two generators separately and a discussion and comparison of the results was presented in order to perceive the dependence of the temperature and dynamic characteristics of the structures. Introductory, a brief survey of recent research progress in monitoring the end-winding vibrations in generators is presented. Subsequently, a detailed description of the performed measurement, starting from the identification of the object and conducted testing methodology according to established standards is systematically exposed. Ultimately, a paramount accent will be put on the experimental results for the measured natural frequencies of the generators, perspectives and propositions on subsequent scientific will definitely not be left out. [ABSTRACT FROM AUTHOR]

This paper elaborates the procedures for scaling prototype structure to scale model according to similitude laws keeping the dynamic properties of the original structure. The scaling procedures are very suitable for experiments where the purpose is not only to check the strength of the structure, but also to investigate the performance of other dynamic devices mounted on the primary structure such as dynamic absorbers. In such cases, the use of condensation methods comes to mind in order to reduce the original d.o.f. and make the model structure behave same in the first several modes as the original structure. [ABSTRACT FROM AUTHOR]

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