The Simulation And Experiment Study On Aircraft Hydraulic Tubes’ Quick Maintenance

The aircraft tubes’maintenance and repair is important work in the whole life cycle of the planes. There are several kinds of tube failure, including rupture, nick, dent, corrosion, erosion and so on. Because the hydraulic system’s working environment is complicated and changeable, tiny faults in the tube will grow up and finally make the whole set of system break down, which will affect the usability and even result in flight accident. Therefore, the good maintenance and overhaul of aircraft hydraulic system is valid measures to make sure the performance and safety.The dent on the tube is the subject investigated. Bulging technique has a wide use at the field of tube forming. We develop the traditional way of hydraulic tube maintenance, contacting it with the bulging technique and use the related theory to instruct the tube maintenance. This research mainly studies the stiff mold bulging and flexible mold bulging. The method of steel cable pulling the bullet is studied in the stiff mold bulging; and it also studies the method of rubber bulging in flexible mold bulging. What’s more, it innovatively comes up with the method of sectional heating and hydraulic bulging in flexible mold bulging. Through simulation and experiment, quality of tube maintenance is studied.The simulation studies the methods of steel cable pulling the bullet, rubber bulging and sectional heating and hydraulic bulging. It studies the effects of the shrink range, displacement of distorted rubber and the hydraulic pressure at 300℃on degree of tube bulging. By analyzing the quality of tube maintenance by spring back, wall thickness and the stress, it finally finds out the suitable shrink range, displacement and pressure, which fit right in with the experiment data.The experiments mainly include the methods of steel cable pulling the bullet and rubber bulging. Based on the self-designed equipments, it studies effects of the shrink range and magnitude of bulging force on quality of tube maintenance. The results prove that a certain shrink range, bulging force and the use of jiggers will make the quality much higher, such as homogeneous wall thickness, smaller spring back.The whole study provides a reference for the aircraft tubes’maintenance, coming to the purpose of saving resources and shortening the production cycle.