Localization of high-frequency vibrations of secondary systems of power plants

Summary

The papers addresses a new approach for more accurate dynamic design of secondary systems and components of nuclear power plants at high frequencies. This approach is based on a precise consideration of a structural member with the rest of the structure being described integrally. The concept is applied to analyse the transition of high-frequency vibrations through non-anchored coupling of structural members which is known to be an effective measure against low-frequency excitation propagation. The theory of high-frequency vibrations is used for integral description of the whole structure. A structural member is represented by an oscillator. A mechanical model comprising a spring in series with a dry damper which has a gap is applied in order to simulate non-anchored coupling of structural members. It is shown that the phenomenon of high-frequency vibration localization takes place for arbitrary mechanical parameters of the structure. This means that the substructure's contact zone possesses a property of high-frequency vibration isolation and the contact surface could be considered as a thin vibroisolating layer which occurs between adjacent coupled substructures.