Computation of mooring systems’ forces of vessels berthed at dolphins

Resumo

The operational safety of a port terminal is assured by the adequate restriction of the ship's movements
by the mooring system, composed of lines and fenders. In the current practice of structural design, the mooring
system's forces are determined by simplified linear analyzes enhanced by dynamic amplification coefficients.
However, the system's stiffness has physical and geometric nonlinearities. Besides, the main forces acting on a
ship at berth come from environmental sources and have random and oscillatory behavior in nature, which may
induce dynamic responses that exceed the static estimated. This work presents partial results of an on-going
research on the dynamic behavior of a vessel berthed at dolphins and the current design practice simplification's
consequences. Different hierarchical models will be analyzed (linear static, non-linear static and linear dynamic)
at a case study of a Floating Storage and Regasification Unit (FSRU) permanently berthed at dolphins at
Barcarena's Liquefied Natural Gas (LNG) terminal, in Pará, Brazil. The results in terms of the mooring system's
forces will be discussed and dynamic amplification coefficients will be estimated.