Ice induced frequency lock-in vibrations - Converging towards consensus

Mauri Määttänen*

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

    4 Citations (Scopus)

    Abstract

    A moving ice field or ice feature hitting a fixed offshore structure will cause different ice load actions as ice can be breaking in different ways depending on ice velocity. At low ice velocities loads are pseudo static or intermittent load fluctuations, and at high ice velocities exhibit random variations. In between is a velocity range where the most severe dynamic ice loading on structure may occur: the frequency lock-in range where ice failures repeat continuously close to a natural frequency in a resonant type of a loading. The capricious frequency lock-in vibrations were encountered already 50 years ago, but even now, the true understanding of the ice-structure interaction based on physical and mechanical properties of both the ice and the structure are not fully understood. Recent advances in scale model testing and numerical analysis of measurement results provide deeper insight on what is really happening in dynamic ice-structure interaction. This development provides a refined understanding on the phenomena during ice failure process against the structure, and how the structure is responding. The final proof is still ahead: acquiring dedicated full-scale data to verify the findings of scale-model tests and the predictions of numerical analysis.

    Original languageEnglish
    Title of host publicationProceedings of the International Conference on Port and Ocean Engineering under Arctic Conditions, POAC
    PublisherLuleå University of Technology
    Volume2015-January
    Publication statusPublished - 2015
    MoE publication typeA4 Article in a conference publication
    EventInternational Conference on Port and Ocean Engineering under Arctic Conditions - NTNU, Trondheim, Norway
    Duration: 14 Jun 201518 Jun 2015
    Conference number: 23

    Publication series

    Name Proceedings : International Conference on Port and Ocean Engineering Under Arctic Conditions
    PublisherPOAC
    ISSN (Print)0376-6756

    Conference

    ConferenceInternational Conference on Port and Ocean Engineering under Arctic Conditions
    Abbreviated titlePOAC
    CountryNorway
    CityTrondheim
    Period14/06/201518/06/2015

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  • Cite this

    Määttänen, M. (2015). Ice induced frequency lock-in vibrations - Converging towards consensus. In Proceedings of the International Conference on Port and Ocean Engineering under Arctic Conditions, POAC (Vol. 2015-January). ( Proceedings : International Conference on Port and Ocean Engineering Under Arctic Conditions). Luleå University of Technology.