SHIP STRUCTURE LOADS AND STRESSES

The investigation was divided into: the testing and further development of known methods of calculating the behaviour of a ship in a seaway which were based on a linearization of the responses with respect to wave height, whereby the extensions were particularly aimed at applications to any kind of ship shapes, including unconventional ones; the determination of nonlinear effects on the behaviour in a seaway, in order to be able to take account especially of the greatest loads and strains excited by heavy seaways; the determination of the elastic vibrations of the ship's hull excited by the seaway, which can cause considerable additional strains. Work on this aspect mainly consisted of determining the exciting and damping forces. Since all effects produced by the natural seaway are of a random nature, analysis of the measurement results, application of theoretical results as well as forecasting of loads and strains is only possible by means of a statistical analysis: short-term statistics in order to compare measurement results with theoretical results for a particular seaway, and long-term statistics in order to compare the loads with the strength of the structure. Still-water stresses are added to those caused by the seaway. They, too, are random quantities amenable to a statistical analysis. To draw attention to this aspect and to show its influence, stowage plans were collected, analyzed and used in preparing a still-water load statistic. The purpose of all these activities was to establish the frequency distribution of the total strains (long-term statistics), from which result, among other things, distributions of the extreme values of the total strains, characteristic values for the fatigue load as well as data which are necessary for the determination of the failure probability of the structure.

  • Corporate Authors:

    Technical University of Hannover, West Germany

    Welfengarten 1
    3000 Hannover,   Germany 
  • Publication Date: 1979-2

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Filing Info

  • Accession Number: 00195795
  • Record Type: Publication
  • Report/Paper Numbers: SFB 98
  • Files: TRIS
  • Created Date: Jul 31 1979 12:00AM