Machinery fault diagnosis has progressed over the past decades with the evolution of machineries in terms of complexity and scale. High-value machineries require condition monitoring and fault diagnosis to guarantee their designed functions and performance throughout their lifetime. Research on machinery Fault diagnostics has grown rapidly in recent years. This paper attempts to summarize and review the recent R&D trends in the basic research field of machinery fault diagnosis in terms of four main aspects: Fault mechanism, sensor technique and signal acquisition, signal processing, and intelligent diagnostics. The review discusses the special contributions of Chinese scholars to machinery fault diagnostics. On the basis of the review of basic theory of machinery fault diagnosis and its practical applications in engineering, the paper concludes with a brief discussion on the future trends and challenges in machinery fault diagnosis.

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Basic research on machinery fault diagnostics: Past, present, and future trends

An improved rotor-blade dynamic model is developed based on our previous works (Ma et al. in J Sound Vib, 337:301–320, 2015; J Sound Vib 357:168–194, 2015). In the proposed model, the shaft is discretized using a finite element method and the effects of the swing of the rigid disk and stagger angles of the blades are considered. Furthermore, the mode shapes of rotor-blade systems can be obtained based on the proposed model. The proposed model is more accurate than our previous model, and it is also verified by comparing the natural frequencies obtained from the proposed model with those from the finite element model and published literature. By simplifying the casing as a two degrees of freedom model, the single- and four-blade rubbings are studied using numerical simulation and experiment. Results show that for both the single- and four-blade rubbings, amplitude amplification phenomena can be observed when the multiple frequencies of the rotational frequency $$(f_\mathrm{r})$$
 coincide with the conical and torsional natural frequencies of the rotor-blade system, natural frequencies of the casing and the bending natural frequencies of the blades. In addition, for the four-blade rubbing, the blade passing frequency (BPF, $$4f_\mathrm{r})$$
 and its multiple frequency components also have larger amplitudes, especially, when they coincide with the natural frequencies of the rotor-blade system or casing; the four-blade rubbing levels are related to the rotor whirl, and the most severe rubbing happens on the blade located at the right end of the whirl orbit.

Nonlinear vibration response analysis of a rotor-blade system with blade-tip rubbing

Prediction of dynamic characteristics of a dual-rotor system with fixed point rubbing—Theoretical analysis and experimental study

Casing vibration response prediction of dual-rotor-blade-casing system with blade-casing rubbing

Blade–casing interaction/rubbing can occur under the small blade-tip clearance, which may lead to the rubbing damage, excessive wear of the abradable coating, and efficiency loss caused by the increasing tip leakage flow. Moreover, the rubbing process involves complicated dynamic phenomena, such as friction-induced wear and heat, coupling vibration of the blade and elastic casing, which has recently received a great concern. This paper provides a review on the dynamic characteristics of blade, rotor, and casing as well as the mechanism of coating wear when the rubbing between the blade and bare or coating casing occurs. Firstly, the modeling methods for blade–casing rubbing are categorized into three types in accordance with different casing types, namely models for the rubbing between the blade and bare casing, models for the rubbing between the blade and coating casing without considering wear, and models for the rubbing between the blade and coating casing considering wear. Then, the simulated blade–casing dynamic characteristics due to rubbing are described for both bare and coating casings. After that, the experimental results of the blade–casing rubbing are reviewed and summarized for the bare and coating casings, respectively. Finally, the open problems for blade–casing rubbings are stated, and some recommendations for future research are also pointed out.

A review on dynamic characteristics of blade–casing rubbing

A new dynamic model of rotor-blade systems

https://hal.archives-ouvertes.fr/hal-01430515/document

A revised model for rubbing between rotating blade and elastic casing

A cyclic sector corresponding to blade-disk structure with dovetail connection (1/38 blade-disk) is studied and the finite element (FE) model of this structure is established based on ANSYS software. A revised normal rubbing force model is developed and a pulse force model is established to simulate the local rubbing phenomenon between the blade and elastic casing based on the revised model. The effects of the rubbing under different rotating speeds and penetration depths on the blade vibration response and contact behaviors of dovetail interface are analyzed. The results show that the rubbing will cause amplitude amplification phenomenon when the multiple frequency components are close to the first bending and first torsion natural frequencies. The arch bending of the blade caused by blade-tip rubbing can be identified by evaluating the displacement and stress of the blade in the radial direction (y-direction). The dynamic stress in the process of rubbing gradually changes from alternation between tensio...

Xingyu Tai

Papers

Nonlinear vibration response analysis of a rotor-blade system with blade-tip rubbing

A review on dynamic characteristics of blade–casing rubbing

A new dynamic model of rotor-blade systems

A revised model for rubbing between rotating blade and elastic casing

Vibration response analysis of blade-disk dovetail structure under blade tip rubbing condition