Abstract Aircraft braking systems may be subjected to friction-induced vibrations, during which the brake is unstable and behaves as a source of mechanical vibrations. This is an issue for aircraft brake manufacturers as it may jeopardize structural integrity due to accelerated fatigue life, or generate discomfort for the aircraft crew and passengers. The important cost associated to the occurrence of this phenomenon motivates the development of instability simulation and prediction methods that can be used as early as the design stage. Here, the self-excited vibrations are induced by a coupling of two structure modes by friction. It appears that modifications of the brake hydraulic command system configuration have important consequences on the vibration levels monitored during the tests. It is therefore necessary, when developing a vibration level simulation methods, to consider the hydro-mechanical coupling of the unstable brake structure with the brake hydraulic fluid. This paper presents a simulation methodology associating a structural reduced model with a unidimensional model of the hydraulic control system, including both passive and active components. Both submodels are validated against experimental data. The influence of several hydraulic system configurations on the coupled system vibration levels and on the braking performances is evaluated. It is shown that a compromise between vibration reduction and braking performance can be found through simulation. It is the first time that the interaction of self-excited brake structure with a heavy fluid is studied. The present method offers important industrial opportunities and gives an insight into the brake mode-coupling dynamics.
Hydro-Mechanical Coupling in Unstable Aircraft Braking Systems
2017-01-01
9 pages
Article/Chapter (Book)
Electronic Resource
English
Hydro-Mechanical Coupling in Unstable Aircraft Braking Systems
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