Structural Health Monitoring for Offshore Wind Turbine Towers and Foundations

Abstract

Abstract Structural Health Monitoring (SHM) of wind turbines can be used for verification and investigation of uncertainties in design, as well as provide input for possible future design optimization. It may also provide early warning of degradation. This allows for condition-based maintenance and status evaluation for possible lifetime extension or changed operational conditions (for example turbine modifications). SHM monitoring applications include environmental loads, corrosion, natural frequencies and damping characteristics of foundations, stress concentrations, deformation, fatigue cycles, foundation scour, seabed stiffness, pore pressure and settlement. Benefits of SHM are described with examples of case studies where monitoring made an important contribution to design improvements. Advantages of integrated monitoring solutions are outlined where an intelligent combination of sensors can provide information of linked parameters and overall assessment of the structural health Recommendations and examples of monitoring systems are described. These cover different foundation types with emphasis on the most significant monitoring aspects for the design of each foundation type. This paper and the detailed report to BSEE provide useful guidelines on structural health monitoring of offshore wind turbine foundations where relevant industry standards presently are missing.