Failure Analysis and Detection Technology Research of Hub Bolts of Aircraft Main Wheel

The hub bolt of the main wheel of a large civil aircraft is an important bearing part in the take-off and landing process of the aircraft. The bolt will be detected by fluorescence or magnetic powder in each tire disassembly process. It is found in the application that even if some bolts pass the magnetic particle detection, they will still break in the process of use. Bolt breakage not only increases the probability of tire damage, but also seriously endangers flight safety. In order to find out the cause of bolt fracture and put forward the corresponding solutions. In this paper, damage bolts are taken for failure analysis, and it is found that most of the fracture positions of threads are located at the root of the fourth thread. According to the characteristics of the fracture, traditional ultrasonic method was used to carry out in-service detection research. The results showed that the shear wave probe with a frequency of K2.2 and 2M could detect 1mm deep cracks at the end of the thread. This method is simple to operate, does not need to dismantle the bolt, can respect the spot construction. The realization of this method is of great significance for flight safety. Keywords—civil aircraft; failure analysis; hub bolt; ultrasonic detection