Talk Title:  A Model Free Approach to Structural Health Monitoring of Composite Wind Turbine Blades

Abstract:

Wind turbine blade failure can be catastrophic and lead to unexpected power interruptions. In this talk, a Structural Health Monitoring (SHM) algorithm is presented for wireless monitoring of wind turbine blades,  The SHM algorithm utilizes strain energy data that are acquired by piezo-electric energy-harvesters. The algorithm compares the accumulated strain energy of sensors located at the same position on the three blades.  The algorithm is “model-free” in that there is no requirement of a priori knowledge of the blade structure or properties.  The premise of this sensing approach is that the timing of signal transmissions is indicative of the structural health of the blade. Signal transmission timings of a damaged blade differ from the timings of undamaged blades so that damage can be detected. This approach exploits the inherent triple redundancy of the blades and avoids the need for a structural model of the blade. The performance of the algorithm is evaluated using probabilistic metrics.  The decision time is chosen to be sufficiently long such that a particular damage level can be detected even in the presence of system sensor noise and wind variations. The effectiveness of the approach will be demonstrated using strain data from a utility-scale 2.5 MW turbine.  

Bio:

Susan Mantell is the James J. Ryan Professor and Head of Mechanical Engineering at the University of Minnesota. Prof. Mantell received her BS and PhD degrees from Stanford University.  Her current research focus is on applications of polymers and polymer composites for engineering structures.  Prof. Mantell is the recipient of several best paper awards from the American Society of Mechanical Engineering, and has received the National Science Foundation Young Investigator Award.  She has also won several student nominated awards for outstanding teaching and received University recognition as the Morse Alumni Distinguished Teaching Professor of Mechanical Engineering.