Random vibration of a finite element rotor model with crack fault via polynomial chaos expansion

Due to long duty hours and stress cycling, crack fault often occurs in rotating shafts. On the other hand, uncertain factors are common in engineering mechanical systems. These uncertainties may have critical influences on the dynamics of the system and the crack fault will be more difficult to accurately detect. In this article, a finite element cracked rotating shaft model is studied considering uncertain factors and the Polynomial Chaos Expansion method is used to quantify their effects on the random vibration of the model. The stiffness of the elastic shaft and the imbalance force are taken as random parameters. Numerical results with different cases are presented. It can provide useful guidance for robust crack fault diagnosis.