Development of embedded sensors for structural health monitiroing of wind turbine blades

Abstract

Monitoring a structure's response to various loading conditions is essential to being able to predict catastrophic failure of the part. There are many types of sensors that have been developed to be able to accurately measure these important quantities. However, as the structure becomes thicker, it is important to monitor in more places than just the surface of the material. Composite materials, such as those used in the wind turbine industry, are typically built in layers, which lend themselves to having sensors embedded in the structure. Previous research had focused on how these embedded sensors affected the mechanical properties of the material, and this research continues on by utilizing the gages to monitor the strains developed in the material. An important aspect of the research was to be able to separate the mechanical strain from the thermal strains developed in the substrate. This was achieved by using advanced circuitry, and was confirmed by performing tensile and heating tests on both surface mounted and embedded sensors. From the data collected, it was shown that it was possible to separate out the mechanical and thermal strains.