高速雨滴冲击下飞行器蒙皮涂层损伤行为动态实验研究

A single waterjet impact test platform was established based on the first-stage light gas gun in order to study the rain erosion damage behavior, to explore the damage mechanism, and to establish the rain erosion damage criterion of the aircraft skin coating. The gas gun launched a lead bullet to impact the nozzle and squeeze the water in the sealing chamber to produce a high-speed jet. Different impact speeds and angles were achieved by adjusting the air pressure and clamp angle. The samples were composed of carbon fiber T300 woven substrate with three types of coatings of the same thickness, and their mechanical properties were measured using the nano-indentation instrument. The test results show that the impact force on the sample increases with the continuous growth of the impact speed of raindrops, resulting in the extension of the damage area and volume loss of the sample. The typical morphology of all the three coating samples is a circular damaged region surrounding the central undamaged area, and presents a circular peeling with the damage increasing. The damage threshold velocity is 360 m/s. With the impact angle increasing, the normal velocity component gradually decreases, and the damage area and volume of the specimen decrease gradually due to the decrease of the instantaneous impact force on the surface of a liquid droplet. Besides, the coating with superior mechanical properties is more prone to damage than the other two coatings due to its rougher surface, the result proves that surface roughness has more significant influence on rain erosion damage of coatings compared to hardness and modulus.