A method for predicting dynamic behavior of an aircraft structure, the aircraft including at least one rotary device including at least one rotor guided in rotation by at least one fixed-bracket bearing containing a shock-absorbing fluid film. The method includes using a global digital model of the aircraft structure including a basic digital model of each rotary device, generating a non-linear digital model of each shock-absorbing film (for example by developing a cavitation-free model and a model with cavitation), integrating the model of each shock-absorbing film with the global model, applying interference to at least one rotor of a rotary device, and calculating the vibration frequency of at least one rotor of each rotary device and the corresponding frequency of the vibrations generated in a critical portion of the aircraft structure.