Low Cost Inspection for Improved Blade Reliability

Wind energy is a level of maturity regarding its value as an alternative energy generation technology. Continued development of wind turbine applications will benefit by ensuring the reliability of wind turbine blade systems. In this work, we explore low cost sensors for composite wind turbine blades to determine Loads, Health Monitoring, and Inspection and Repair. Items to be sensed for improved composite wind turbine blade reliability include wind velocity, temperature, blade strain, moisture/humidity, blade acceleration, blade tip deflection, and damage initiation. Representative wind turbine blade laminates were made with embedded and post-processing integrated sensors. Sensors studied to date include Polyvinylidene Fluoride (PVDF) piezo electric polymer sensors for strain and transient loadings, accelerometers, embedded metal foil strain gages, ambient humidity sensors, thermocouples, IR transmittance for quality, and fiber optic sensors for a variety of sensing applications. Major conclusions from this work are that low cost sensors are feasible and can be implemented into composite wind turbine blade laminates. Data acquisition has been developed in a robust, commercially available platform. Embedding sensors into wind turbine blade laminates will not be trivial; composite/sensor interface and static strength problems were confronted in the present work. The durability of the sensors and composite laminates with sensors remain outstanding issues for the deployment and utilization of sensors for composite wind turbine blades.