The Dynamics of Geometrically Compliant Mooring Systems

Abstract

Geometrically compliant mooring systems that change their shape to accommodate deformations are common in oceanographic and offshore energy applications. This thesis describes a numerical program and experimental results which are used to develop an understanding of the dynamic response of these systems. A numerical program is described which uses the generalized-a method for temporal integration. Compared to other schemes, the generalized-a algorithm has the advantages of second-order accuracy, controllable numerical dissipation, and improved stability for the nonlinear problem. The numerical program is validated using results from laboratory and field experiments. Field experiment and numerical results are used to develop a simple model for dynamic tension response in geometrically compliant moorings. For most moorings, the response is dominated by inertial and drag effects. The simple model uses just two terms to accurately capture these effects. The interaction of the mooring line with the sea floor is considered. Using video and tension data from laboratory experiments, the tension shock condition at the touchdown point and its implications are observed for the first time. Results from the laboratory experiments are also used to demonstrate the suitability of the elastic foundation approach to modeling sea floor interaction in numerical programs.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2000
Accession Number
ADA384976

Entities

People

  • Jason I. Gobat

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Computational Fluid Dynamics
  • Computational Science
  • Coordinate Systems
  • Difference Equations
  • Differential Equations
  • Dynamic Response
  • Equations Of Motion
  • Failure Mode And Effect Analysis
  • Finite Element Analysis
  • Geometry
  • Global Positioning Systems
  • Image Processing
  • Oceanography
  • Partial Differential Equations
  • Resonant Frequency
  • Three Dimensional
  • Two Dimensional

Readers

  • Computational Modeling and Simulation
  • Marine Hydrodynamics
  • Structural Dynamics.