Nonlinear Dynamic Behaviors of a Marine Rotor-Bearing System Coupled with Air Bag and Floating-Raft

We, Zhao; Li, M.; Xiao, Longfei

doi:10.1155/2015/620968

Cited by 5 publications

(5 citation statements)

References 8 publications

(9 reference statements)

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“…According to the time series of MTSB, the degradation process of accuracy is defined as a Poisson process, and the degradation probability is taken as a parameter of the counting process [28]. Influenced by many factors, the degradation process of bearings has the characteristics of non-linear dynamics [29,30]. For each time series of accuracy, the degradation probability relative to the intrinsic series also has the characteristics of non-linearity and diversity.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Evaluation of the Degradation Process of Vibration Performance for Machine Tool Spindle Bearings

Liang

Zhang

Cui

et al. 2023

Sensors

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Real-time condition monitoring and fault diagnosis of spindle bearings are critical to the normal operation of the matching machine tool. In this work, considering the interference of random factors, the uncertainty of the vibration performance maintaining reliability (VPMR) is introduced for machine tool spindle bearings (MTSB). The maximum entropy method and Poisson counting principle are combined to solve the variation probability, so as to accurately characterize the degradation process of the optimal vibration performance state (OVPS) for MTSB. The dynamic mean uncertainty calculated using the least-squares method by polynomial fitting, fused into the grey bootstrap maximum entropy method, is utilized to evaluate the random fluctuation state of OVPS. Then, the VPMR is calculated, which is used to dynamically evaluate the failure degree of accuracy for MTSB. The results show that the maximum relative errors between the estimated true value and the actual value of the VPMR are 6.55% and 9.91%, and appropriate remedial measures should be taken before 6773 min and 5134 min for the MTSB in Case 1 and Case 2, respectively, so as to avoid serious safety accidents that are caused by the failure of OVPS.

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Section: Introductionmentioning

confidence: 99%

Dynamic Evaluation of the Degradation Process of Vibration Performance for Machine Tool Spindle Bearings

Liang

Zhang

Cui

et al. 2023

Sensors

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“…Figure 3 illustrates the bifurcation diagram based on the above initial condition and shows the theoretically calculated bifurcation diagram of the mechanical isolation system with respect to the key motion parameter ω, in which ω varied from 0.60 to 3.50. It can be summarized from the bifurcation diagram (a) that the main influences by basic excitation on the mechanical isolation system are mainly concentrated in the low rotating speed stage, where the system amplitude is large in comparation with the prior research [26] and the response shows a periodic motion. With the rapid increments of rotor speed, the system vibration decreases gradually in the vertical direction.…”

Section: Bifurcation Diagram Because Equationmentioning

confidence: 99%

Nonlinear Dynamics of Marine Rotor System Coupled with Air Bag-Floating Raft Subjected to the Basement Excitations in Lateral Directions

Liu

2020

Shock and Vibration

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This paper presents an investigation into the nonlinear dynamic behaviors of the mechanical isolation system coupled with air-bag and floating-raft subject to basement excitation in lateral directions. First, the coupling effects between the excitation source and isolation system are considered. Also, the mechanical isolation model under basic excitation and its motion equation are deduced, and then the dynamic responses are mainly investigated by using the techniques of displacement response, frequency spectrum, rotor orbit, Poincaré maps, and the bifurcation diagram. Last, the bifurcations of the mechanical isolation system with different parameters are analyzed through numerical methods, especially the effect of excitation frequency and amplitude. The result predicts that period-5 is mainly performed, with the increase of rotor speed, and the system moves into quasi-bifurcation. However, the system stays in chaos state at high rotor speed, and the vibration amplitude rises rapidly until against bearing bush. Furthermore, the effects of basement excitation on the mechanical isolation system are mainly concentrated on the stage of lower rotor speed, but with the increasing speed, the effects become weak and at the same time the vibration amplitude reduces significantly. The points projected on the Poincaré section are five, three, or two solitary attractors, in which the system stays in periodic motion. Above all, the dynamic characteristics can provide the theoretic supporting for the dynamic, vibration control and its parametric optimization of the marine mechanical isolation system coupled with air-bag and floating-raft.

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“…Li et al 34 introduced the nonlinear vibration isolation floating raft system and derived approximate analytical solutions of the system on multiple scales. A dynamic model of a rotor-bearing system coupled with the airbag and the floating raft was established by Zhao et al, 35 and a numerical method was employed to obtain the response of the system. Moreover, Liu et al 36 studied the effect of a floating raft isolation system on the vibration behaviour of a marine pump.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear dynamics of the rotor system with a floating raft isolation structure under the coupled motion of ship heaving and rolling

Xie

Wang

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part K:

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A floating raft isolation structure is adopted to reduce the vibration of the marine rotor-bearing system, however, the system on the moving hull will be affected by the ship implicate motion, and its vibration will be difficult to predict. In this study, a dynamic model of the system under heaving and rolling coupled motion is established after considering the nonlinear oil film reaction force, unbalance inertia force, restoring force of the structure and inertia force of the ship motion. A numerical method is introduced to present the responses of the system, such as the amplitude and rotating speed curve, waterfall diagrams, and the rotor orbit and its Poincaré maps, etc. Moreover, the effects of rotating speed, amplitudes and frequencies of the coupled motion on the dynamic behaviours of the system are studied. The results indicate that the unstable region of rotating speed of the system increases under the coupled motion, the vibration of the system is greatly affected by the parameters of coupled motion, and the vibration amplitudes of rotor and raft can be effectively limited due to the displacement restrictor.

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Nonlinear Dynamic Behaviors of a Marine Rotor-Bearing System Coupled with Air Bag and Floating-Raft

Cited by 5 publications

References 8 publications

Dynamic Evaluation of the Degradation Process of Vibration Performance for Machine Tool Spindle Bearings

Dynamic Evaluation of the Degradation Process of Vibration Performance for Machine Tool Spindle Bearings

Nonlinear Dynamics of Marine Rotor System Coupled with Air Bag-Floating Raft Subjected to the Basement Excitations in Lateral Directions

Nonlinear dynamics of the rotor system with a floating raft isolation structure under the coupled motion of ship heaving and rolling

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