PROBABILISTIC INSTABILITY AND RESPONSE OF SURFACE SHIPS.

Abstract

The first part of report is concerned with the probability of instability on a straight course of ships moving in a lateral plane. The hydrodynamic coefficients in the differential equations of motion are considered to be random variates. A criterion for the probability of instability is derived, which is then applied to a MARINER type ship which is known to be near a state of marginal stability on a straight course. The second part of report discusses the probability density functions of the heading rate in a turning maneuver when one or more steering indices are random variates. In particular, the probability density functions are derived for the heading rate response of a ship with a step-type rudder input. The theoretical results are applied to a small cargo ship. It is shown that at very large values of time, the probabilistic response differs considerably from the deterministic response. A procedure for predicting the response in terms of the dimensions and displacement of a ship is also developed and discussed. This procedure appears to be a promising design approach which facilitates the maneuvering capabilities of preliminary designs. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1968
Accession Number
AD0673320

Entities

People

  • Adolf G. Strandhagen

Organizations

  • University of Notre Dame

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Cargo Ships
  • Differential Equations
  • Equations
  • Equations Of Motion
  • Instability
  • Partial Differential Equations
  • Probability
  • Probability Density Functions
  • Ships

Fields of Study

  • Mathematics

Readers

  • Control Systems Engineering.
  • Mathematical Modeling and Probability Theory.
  • Naval Architecture and Marine Engineering.