船舶復原性より見たる安全示數

書誌事項

タイトル別名
  • Safety Criterion of a Ship considered from the Stability

説明

When a ship, which is rolling among waves around the steady heel due to wind, is attacked by a sudden gust, sometimes accompanied by the rudder action, if the work done by the gust and rudder action be greater than the reserve of her stability, she capsi es. The condition, that the capsize may not occur, can be expressed by the following relations:<br>C'=Sd/CwDwr+2θ0) 2D0θ0+1/2mθ02>1......(A)<br>where Sd: dynamical stability arm, i. e. the area of t e stability curve divided by the weight of the ship, Dw: heeling moment arm (the speed of the gust assumed to be 1.4 time of the mean wind speed), θr: range of the stability curve, Cw: reduction coefficient determined from the fact of the reduction of wind speed near the sea level, θ0: rolling angle. D0: heeling moment arm due to the rudder action, m: metacentric eight.<br>Being given the speed and the rolling period of a ship, the waves (length and height) and wind speed, which cause the severest conditions to her heel, are to be found from the curves given in the paper. C' in (A) should be at least greater than unity, but, considering the other conditions which are not taken into account in the deduction of (A), the permissible lowest value of C' must be taken much greater than unity. C' is called in this paper the safety criterion, and can be considered as like the factor of safety in the strength of materials, and its permissible lowest value should be determined from the experiences of actual ships. Values of C' are calculated with several small-typed vessels, and given in the Table.

収録刊行物

  • 造船協會會報

    造船協會會報 1948 (79), 9-21, 1948

    社団法人 日本船舶海洋工学会

詳細情報 詳細情報について

  • CRID
    1390001205355164288
  • NII論文ID
    130003888235
  • DOI
    10.2534/jjasnaoe1903.1948.9
  • ISSN
    18842054
  • データソース種別
    • JaLC
    • Crossref
    • CiNii Articles
  • 抄録ライセンスフラグ
    使用不可

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