Scientific advances and innovation

The objective of the ColFOWT project is to develop and validate a fast and reliable collision analysis tool, specific for floating offshore wind turbines, based on analytical formulations (super elements derived from plastic limit analysis) coupled with a large rotational floating structure movement solver.

Expected technical and economic impact

By including the action of the mooring lines on the platform rigid body movements during and after the collision, the tool developed in ColFOWT will allow design offices to assess, at pre design stage, the consequences of a collision in term of ship and wind turbine damage. Thanks to its rapidity, the ColFOWT tool will also allow both the classification societies and the traffic regulatory authorities to simulate all the scenarios requested for a complete risk analysis. Situations that may be dangerous for the wind farm or/and for the different ships navigating in the vicinity will thus be identified.

Key project milestones

  • October 2019 - Kick-Off of the project
  • September 2022 - Closure of the project


In a first step, Finite Element Analysis of the collision of an Offshore Supply Vessel against a Spar Floating Offshore Wind Turbine allowed to identify the main damage mechanisms as well has the significance of hydrodynamic effects. A deep study of the energy balance also allowed to highlight some limitations of Ls-Dyna / MCOL package.
In a second step, analytical models based on plastic limit analysis have been developed to assess the resistant force related to the different successive deformation modes. These models have been successively confronted to numerical results for high impact energies. However, it has been shown that the elastic contribution remains significant and must be considered when the impact energy is low or moderate.
In parallel, the impact response of a reinforced concrete slab has been simulated and several behavior laws implemented in Ls-Dyna have been confronted to documented experimental tests. Existing analytical models able to assess the slab resistant force have also been studied. Then, an analytical model based on closed-form expressions have been developed and successfully confronted to experimental results extracted from the literature.
Finally, the future experimental campaign (to be held at the end of this year) where reinforced concrete beams will be impacted has been prepared.


Publications and papers published