Abstract:Aiming at the problems of complicated vibration mechanism, strong fault correlation, insignificant fault characterization, and low identification rate of early crack failure and propagation state of aviation hydraulic pipeline, a fault diagnosis method based on fractal theory was proposed.Firstly, by using the fractal theory that could be used to solve complex fractal problems, the sinecosine signals were simulated and their generalized dimension were calculated. According to the calculation results, the generalized fractal dimension could be used to describe the signal characteristics. Secondly, fractal analysis was carried out on the vibration signal by using the generalized dimension, according to the spectrum diagram of generalized dimension and the variation rule of generalized dimension, the generalized dimension could not only diagnose whether there was crack fault in the aviation hydraulic pipe, but also identify the early fault and crack propagation state.Finally, the fractal generalized fractal dimension table shows that the value of the fractal dimension increases with the increase of the crack length, and the value of the fractal dimension increases exponentially. Therefore, the crack propagation state of the hydraulic pipe can be quantitatively analyzed by the change of the fractal dimension.