Faculté des Sciences appliquées
Faculté des Sciences appliquées

Validation of the ColFOWT collision assessment tool for ship/offshore wind turbines

Vandegar, Gabriel ULiège
Promotor(s) : Rigo, Philippe ULiège
Academic year : 2022-2023 • Permalink :
Title : Validation of the ColFOWT collision assessment tool for ship/offshore wind turbines
Translated title : [fr] Validation de l'outil d'évaluation des collisions ColFOWT pour les navires/éoliennes offshore
Author : Vandegar, Gabriel ULiège
Advisor(s) : Rigo, Philippe ULiège
Committee's member(s) : Rigo, Philippe ULiège
Language : English
Number of pages : 88
Keywords : [en] Ship Collisions, Offshore Wind Turbines, Simplified Methods, Finite Element Analysis.
Discipline(s) : Engineering, computing & technology > Mechanical engineering
Name of the research project : ColFOWT project
Target public : Researchers
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master : ingénieur civil mécanicien, à finalité spécialisée en "Advanced Ship Design"
Faculty: Master thesis of the Faculté des Sciences appliquées


[en] The consequences of ship collisions against offshore wind turbines can range from minor
structural damage to catastrophic failure, depending on various factors such as vessel initial
kinetic energy, impact location, and geometry. To address this critical issue, the ColFOWT
(Collision against Floating Offshore Wind Turbines) project focuses on developing a rapid
collision assessment tool that integrates closed-form analytical models. This tool predicts the
complex energy transfer processes during impacts and aims to validate its accuracy through
numerical simulations using the LS-DYNA non-linear FEM package.
In this mater thesis, the analytical tool for spar-buoy floating platforms is presented. The
developed method adopts a semi-coupled approach, using the rigid-body dynamics program
MCOL to simulate the external dynamics of the floating wind turbine. Meanwhile, internal
mechanics are computed using an elasto-plastic simplified method for the impact response of
standalone tubular offshore wind turbine supports. An overview of the algorithm is provided,
including a detailed explanation of both internal mechanics and external dynamics solvers, along
with the coupling method.
The presented collision tool is validated by comparing it against simulations conducted with
LS-DYNA/MCOL. The case study involves various offshore supply vessels impacting, with
varying initial velocities, an NREL 5 MW baseline turbine mounted on an OC3 Hywind
reference spar platform. The results demonstrate that in most of the cases, the analytical tool
is able to capture quite accurately the response of both the turbine and the vessel, accounting
for the action of both the surrounding water and the mooring lines. Its current limitations
are also highlighted and, although there is still room for improvement, this user-friendly and
cost-effective complementary tool shows good accuracy for the early-design stage.



Access Gabriel_Vandegar_These.pdf
Size: 8.81 MB
Format: Adobe PDF


  • Vandegar, Gabriel ULiège Université de Liège > Master ing. civ. méc. (EMSHIP+)


Committee's member(s)

  • Total number of views 27
  • Total number of downloads 88

All documents available on MatheO are protected by copyright and subject to the usual rules for fair use.
The University of Liège does not guarantee the scientific quality of these students' works or the accuracy of all the information they contain.