TO MODAL CHARAC- TERISTIC OF ROTOR SYSTEM

Xu Yuxiu

(School of Mechanical and Electronic Engineering, Tianjin Polytechnic University, Tianjin 300160)

Zhong Jianjun

(Institute of Military Traffic, PLA, Tianjin 300161)

Wen Bangchun

(Institute of Mechatronical Engineering and Automation, Northeast University, Shenyang 110006)

Abstract: The multi-fractals theory is applied for proposing the calculation formula of general dimension least square method. The general dimension of measured time domain signal is calculated, the sequence value of general dimension is obtained, and the box dimension, the information dimension, the correlation dimension and the sensitive dimension are got from general dimension. The general dimension of the fault sample is calculated. And the relationship between fault and fractal is found out. These provide the basis of analyzing the fault strength by fractal dimension. In addition, combined general dimension sequence value and mathematics method, the fractal diagnosis classification is proposed. It achieves good results to diagnose, identify and classify the measuring and modal coupling fault signal by the utilizing theorem of the general dimension maximum correlation coefficient and the general dimension sequence signal value. Through the example of the rotor system fault diagnosis, it explains that the fractal dimensions abstracted from the general dimension can better diagnose, identify the fault and its degree. The method of fractal diagnosis and classification has better actual effective property.

Key words: Multi-fractal theory  Fault sensitive dimension  Modal fractal characteristic  Coupling fault diagnosis  Fractal diagnosis and classify

CLC No: TH113.1  TH165.3

国家自然科学基金资助项目(50275024). Received 20050224, received in revised form 20050808