A Method for Damage Detecting of Large Reflector Antennas Wheel-Rail Based on Electromagnetic Ultrasonic Technology

Abstract

The azimuth wheel-rail of large reflector antennas is one of the key components, it not only supports the whole weight of the antenna, but also directly affects the antennas' pointing performance by its surface accuracy. Usually, the whole weight of the large reflector antenna is thousands of tons, its azimuth frame rollers have great contact stress with the wheel-rail surface, repeated rolling can cause rolling contact fatigue on the wheel-rail surface, resulting in wear, cracks and other damage to the wheel-rail, and even lead to failure or fracture of the wheel-rail in serious cases, so it is very important to monitor the damage of the antenna wheel-rail. Current studies are based on Hertzian theory for stress analysis of rollers and wheel-rails, it cannot visually determine the damage. In order to visually detect the usage of antenna wheel-rail surfaces, this paper, for the first time, proposed the method using electromagnetic ultrasonic detection to detect the damage of antenna wheel-rail surface. Based on the principle of electromagnetic ultrasonic nondestructive testing, the simplified wheel-rail model containing wear, corrosion and crack damages are simulated. The results show that this method can effectively detect the surface damage of the antenna wheel-rail surface, and it can provide an important reference for the research of wheel-rail damage detection of large reflector antennas.