Research on infrared nondestructive testing and thermal effect analysis of small wind turbine blades under natural excitation

•The infrared nondestructive testing experiment under natural excitation is carried out on the blades with wear damage, and the best light conditions are obtained.•Through the physical modeling method of fluid-thermal-solid coupling, the simulation of scene reconstruction is carried out, and the experimental results are in good agreement with the simulation results.•Based on the simulation model, the influence of wind speed on the temperature, pressure and stress at the damaged blade is studied. At the same time, from the actual project, the influence of wind direction on the temperature, pressure and stress at the damaged blade is also studied.