Analysis of vibration characteristics of inter-shaft bearing with local defects based on multi-body dynamics

In order to study the vibration characteristics and contact stress of an inter-shaft bearing with local defects，a two-dimensional fully flexible dynamic model of the inter-shaft bearing with single and compound faults was established based on the multi-body dynamics method. With this model，the time-frequency distribution characteristics and contact stress variation law of the inter-shaft bearing with local defects were analyzed. Compared with the lumped parameter model based on nonlinear Hertz contact theory and the experimental results，the accuracy of the multi-body dynamics model was verified. The research results showed that the error between the fault characteristic frequency obtained based on the established model and the lumped parameter model and the experimental results was less than 1%. The maximum value of the equivalent contact stress of the bearing appeared at the fault crack，spread around and reduced; the contact stress in the bearing area was significantly higher than that in the non bearing area，and the time interval of the change of the equivalent stress was the reciprocal of the fundamental frequency of the inter-shaft bearing fault characteristic frequency. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.