To ensure the availability and operational safety of wind turbine blades, regular inspections are required according to specified maintenance intervals. As with all periodic inspections, damage that develops between two inspection dates remains undetected until the next inspection. In recent years, monitoring systems have therefore been developed that enable independent structural health monitoring (SHM) with permanently installed sensors. The most important representatives here include vibration analysis, acoustic emission testing and ultrasonic methods. In addition, it is necessary for an SHM system to distinguish between signal changes resulting from damage or changing environmental and operating conditions. The present work presents a new approach for the in-situ assessment of wind turbine blades via embedding radar networks in the frequency band from 58 to 63.5 GHz. Therefore, 40 FMCW (frequency-modulated continuous wave) radar sensors have been embedded into a wind turbine blade during manufacturing. This contribution provides additional information related to the hardware design of the sensor nodes, its preliminary testing and the specific implementation of the radar network during a fullscale fatigue test of a 31m long wind turbine blade [1]. Damage indicators can be formulated relative to baseline conditions to see the development of fatigue damage over time. Reference: [1] Simon, J.; Kurin, T.; Moll, J.; Bagemiel, O.; Wedel, R.; Krause, S.; Lurz, F.; Nuber, A.; Issakov, V. & Krozer, V., Embedded Radar Networks for Damage Detection in Wind Turbine Blades: Validation in a Full-scale Fatigue Test, Structural Health Monitoring, 2023, https://doi.org/10.1177/14759217231152815
Read full abstract