Operations and maintenance costs for offshore wind plants are estimated to be
significantly higher than the current costs for onshore wind plants. One way to reduce these
costs would be to implement a structural health and prognostic management (SHPM) system
as part of a condition based maintenance paradigm with smart load management. To
facilitate the development of such a system a multiscale modeling approach has been
developed to identify how the underlying physics of the system are affected by the presence
of damage and faults, and how these changes manifest themselves in the operational
response of a full turbine. This methodology was used to investigate the effects of rotor
imbalance and shear web disbond on a 5-MW offshore wind turbine in the present report.
Based on simulations of the model, the operational measurements that demonstrated the
highest sensitivity to the damage/faults were the blade tip accelerations and local pitching
moments for both imbalance and shear web disbond. Detection strategies have been
developed for these fault mechanisms with the intent of being integrated into an operations
and maintenance paradigm. The integration of the health monitoring information provides
the initial steps to reducing operations and maintenance costs for an offshore wind farm
while increasing turbine availability and overall profit.