Research on infrared nondestructive detection of small wind turbine blades

To obtain the optimal light conditions for field infrared nondestructive detection of wind turbine blades, this paper used a 2kw small wind turbine blade with different damage types and degrees of damage as the research object. Using the passive infrared thermal imaging detection method, the damage of the wind turbine blade was naturally stimulated under outdoor conditions with enough light in summer to collect infrared thermal images, and the numerical simulation of the damage was performed. The experimental and simulation results show that light intensity has a large influence on damage detection, and the three typical damage of the best detection conditions are obtained. Among them, the light intensity of a foreign body attached reaches 950 W/m2 or higher for the best detection effect, while facial wear and crack damage were best detected at a light intensity of around 1000 W/m2 in the sunny noon. The simulation results agree well with the experimental results when using COMSOL multiple physical field coupling software for wear and crack damage scene reconstruction of finite element simulation, proving that the use of solar radiation as a source of passive infrared thermal imaging detection technology to detect wind turbine blade damage within a certain range of light intensity is feasible. Meanwhile, the numerical model was used to thermodynamically couple the wear-damaged blade, yielding a positive linear relationship between light intensity and the blade's highest temperature, stress, and strain. Furthermore, the degree of wear damage and the stress-strain corresponding to the highest temperature of the blade are both positively linear.