Retraction system performance analysis of landing gear with the influence of multiple factors

The landing gear retraction system is a mixed complex system consisted of mechanism, electricity and hydraulics. The retraction performance is affected by various factors. In most of the current studies, the subsystems are not well combined. Thus, a set of method combining theoretical analysis, multidisciplinary simulation and test verification was put forward, which provided a more accurate analysis method for the landing gear retraction system. Firstly, the dynamics equations of the retraction system were derived by power bond graph in detail. Then, a multidisciplinary simulation model was established, which combined the mechanism dynamics with the hydraulic system. This virtual prototype was verified by contrasting its results with the test results. At last, the key parameters' influence on the landing gear retraction performance was studied. The results show that, the pressure curves of the co-simulation model agree well with the ones of the test. Meanwhile, some key parameters, including crosswind, friction, damper orifices, liquid capacity and oil leak, affect the landing gear retraction performance in different degrees. Some meaningful results are concluded, which can be used as the guidances of the determination of retraction system parameters, the retraction fault analysis and the reliability study. ©, 2015, Beijing University of Aeronautics and Astronautics (BUAA). All right reserved.