Risk assessment: loss of structural integrity

Tower failure and loss of nacelle or blade fragments are rare events but can cause serious damage if objects like public roads or pipe lines are within reach of the fragments.

In these cases the resulting risk need to be assessed site specifically taking into account the local situation and wind conditions.

The trajectory of the rotor blade or large fragments of the rotor blade needs special attention as this is strongly dominated by the aerodynamic properties of the blade profiles.

Therefore we base the calculation of the trajectories of a blade fragment on its aerodynamic coefficients, geometry and mass distribution and track the three dimensional orientation of the fragment through space and time. This gives much more realistic results compared to a simple ballistic trajectory and enables us to catch those events where lift forces expand the trajectory length significantly. The following figure visualizes the calculated trajectory of a large blade fragment.

We calculate a total of several million trajectories for different boundary conditions to determine the impact probabilities within the surrounding of the wind turbine.

Based on this the specific risks can be evaluated for your project. Typically injury to persons is in the focus of the assessment.

We will be glad to support your project and provide our experience in this field.