Microwave Structural Health Monitoring of the Grouted Connection of a Monopile-Based Offshore Wind Turbine: Fatigue Testing Using a Scaled Laboratory Demonstrator

Figure 19

Transfer function-based damage indicator (a) and skewness of strain signals (b) during hydraulic excitation at four load levels and the measurement positions Ga1-Ga5 at the outer pipe resp. Gi0-Gi5 at the inner pipe.

(a)

(b)