Dynamical Behaviors Analysis of the Rotor Model with Coupling Faults and Applications of the TPOD Method

Kuan Lu,Kangyu Zhang,Chao Fu,Yulin Jin,Nan Wu,Haopeng Zhang,Yongfeng Yang

doi:10.3390/app10217415

Abstract

The transient proper orthogonal decomposition (TPOD) method is applied for order reduction in the rotor-bearing system with the coupling faults in this paper. A 24 degrees of freedom (DOFs) rotor model supported by a pair of sliding bearings with both crack and rub-impact faults is established by the discrete modeling method. The complexity of dynamic behaviors of the rotor system with the coupling faults is discussed via the comparison of the rotor system with the single fault (crack or rub-impact). The proper orthogonal mode (POM) energy method is proposed to confirm the DOF number of the reduced model. The TPOD method is used in the coupling faults system to obtain the optimal order reduction model based on the POM energy. The efficiency of the order reduction method is verified by comparing the bifurcation behaviors between the original and the reduced system. The TPOD method provides the optimal order reduction model to study the non-linear dynamic characteristics of the complex rotor system with the coupling faults.

Highlights

The influence of the faults in the rotating machines on the associated dynamic behavior has been a focus of attention for many researchers
The non-linear dynamic characteristics of the rotor system with the coupling faults have been discussed in this paper
A 24-DOFs rotor system supported by a pair of sliding bearings with both crack and rub-impact faults has been established by the Newton’s second law

Summary

Introduction

The influence of the faults in the rotating machines on the associated dynamic behavior has been a focus of attention for many researchers. On the basis of the common faults in the rotor systems, the coupling faults (the looseness and rub-impact, the crack and rub-impact, etc.) usually occur in the actual rotor systems. The amplitude varies when the cracked rotor is operating, which will lead to the rub-impact with other units of the rotating machine. If the rub-impact fault occurs, the crack of shaft or impeller may occur on account of the harsh operating conditions and the strong influence. Few researchers studied the rotor systems with the coupling faults, since they are more complex than the systems with only single fault [20]. The dynamical characteristics of the rotor systems with the complex coupling faults should be further explored

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Conclusion