EVALUATION OF METHODS FOR EXTRAPOLATION OF SHIP BENDING STRESS DATA

This report is a continuation of an earlier report (Report SSC-196, June 1969), giving results of the analysis of all available stress data from full-scale, measurements on the following dry cargo ships: S. S. WOLVERINE STATE, S.S. HOOSIER STATE, S.S. MORMACSCAN, and S.S. CALIFORNIA BEAR. The results for the first two, which are sister ships of the C4-S-B5 type cover a total of about 10 ship-years in the North Atlantic, and results are felt to be consistent and reliable. Results for the MORMACSCAN, covering brief periods in the runs from New York to Europe and New York to South America, appear to provide inadequate statistical samples. CALIFORNIA BEAR results for the North Pacific appear to be reasonable for that service. Further details are given on two techniques for the analysis and extrapolation of full-scale data to longer periods of time, in order to predict extreme bending stresses (or bending moments) in service. One of the techniques employs the integration of rms stress data from individual stress records; the other makes use of the highest stresses obtained in each record (extreme values). Both techniques involve the classification of data by severity of weather in order to obtain greater generality of results. It is shown that extrapolated trends from two methods are consistent. Comparisons are made of non-dimensional bending moment coefficients for all of the ships on the basis of the same "standard" weather distribution.

  • Corporate Authors:

    Ship Structure Committee

    National Academy of Science, 2101 Constitution Avenue, NW
    Washington, DC  USA  20418
  • Authors:
    • Hoffman, D
    • Van Hooff, R
    • Lewis, E V
  • Publication Date: 1972-8

Media Info

  • Features: References;
  • Pagination: 41 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00040604
  • Record Type: Publication
  • Source Agency: Ship Structure Committee
  • Report/Paper Numbers: SSC-234
  • Contract Numbers: N00024-68-C-5282
  • Files: TRIS
  • Created Date: Feb 14 1973 12:00AM