Dynamics of Two-Line Ship Towing/Mooring Systems: Bifurcations, Singularities of Stability Boundaries, Chaos Academic Article uri icon

abstract

  • A methodology is developed for analysis and design of two-line towing and mooring (TLT/M) systems based on their nonlinear, horizontal-plane, slow-motion dynamics. The time evolution of the corresponding autonomous dynamical system is described in a six-dimensional state space. Branching diagrams identify supercritical pitchfork bifurcations and turning points which result in static loss of stability. TLT/ Ms also exhibit Hopf bifurcations which result in dynamic loss of stability and periodic solutions. Stability charts are developed to show catastrophe sets and regions of qualitatively different dynamics. Thus, regions of hazardous dynamics and line breakingsuch as unstable equilibrium, unstable limit cycle, and chaotic dynamicsare identified. Theoretical conclusions are verified by numerical simulations of tanker and barge TLT/Ms. Based on this methodology, only a limited number of simulations is needed for analysis and design of TLT/Ms. Lines can be selected then to complementrather than countereach other and allow the system to attain a safe equilibrium.

published proceedings

  • Journal of Ship Research

author list (cited authors)

  • Chung, J., & Bernitsas, M. M.

citation count

  • 10

complete list of authors

  • Chung, Jin-Sug||Bernitsas, Michael M

publication date

  • January 1992