A STUDY OF THE DISTRIBUTION OF MAXIMA OF NON-LINEAR SHIP ROLLING IN A SEAWAY

The report describes the methods and results of a digital computer simulation of a non-linear random process analogous to one of the simpler analytical models for ship roll. The main objective of the simulation was to obtain 'empirical' data on the distribution of roll maxima, and to test these data against the corresponding theoretical distributions for a random Gaussian (linear) process. Effort was made to confine the variation of parameters within ranges appropriate to ship rolling. Within this range of parameters, the frequency band of roll response is sufficiently narrow that the theoretical distribution of maxima of the corresponding linear process tends toward the Rayleigh. The results obtained by objective statistical test procedures, indicate that the distribution of maxima of the non-linear process is not Rayleigh in a substantial portion of the parameter range of interest. However, it was possible to conclude from the results that the Rayleigh assumption is reasonable for an important class of engineering predictions; that of the prediction of average, 'significant' and '1/10 highest' maxima from a knowledge of the spectrum of roll. (Author)

• Corporate Authors:

  Stevens Institute of Technology

  711 Hudson Street
  Hoboken, NJ  United States  07030
• Authors:
  • Dalzell, J F
• Publication Date: 1971-9

Media Info

• Pagination: 161 p.

Subject/Index Terms

• TRT Terms: Rolling; Ship motion; Ship simulators; Simulation
• Old TRIS Terms: Roll amplitude; Roll simulation; Ship response
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00033621
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: SIT-DL-71-1562
• Contract Numbers: N00014-67-A-02020026
• Files: TRIS
• Created Date: Aug 15 1972 12:00AM