Multi-channel Active Vibration Isolation for the Control of Underwater Sound Radiation From A Stiffened Cylindrical Structure: A Numerical Study

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Huang Xiuchang ◽  
Zhang Zhiyi ◽  
Zhang Zhenhua ◽  
Hua Hongxing
Keyword(s):  
Cylindrical Shell ◽  
Vibration Isolation ◽  
Sound Radiation ◽  
Spatial Average ◽  
Far Field ◽  
Underwater Sound ◽  
Cylindrical Structure ◽  
Vibration Isolators ◽  
Active Vibration ◽  
Active Vibration Isolation

Numerical simulation of vibration control of a submerged stiffened cylindrical structure with active vibration isolators is presented. Vibration transmission from vibrating machinery to the cylindrical structure through the active vibration isolators is analyzed by a numerical model synthesized from frequency response functions (FRFs) and impedances. The coupled finite element/boundary element (FE/BE) method is employed to study the vibro-acoustic behavior of the fluid-loaded cylindrical structure. Sound pressure in the far-field is calculated in terms of the pressure and normal acceleration of the outer surface of the cylindrical shell. An adaptive multichannel control based on the filtered-x least mean squares (FxLMS) algorithm is used in the active vibration isolation. Simulation results have demonstrated that suppression of vibration of the four elastic foundations attached to the cylindrical shell will reduce the spatial-average mean-square velocity and the instantaneous radiated power of the cylindrical shell. As a result, suppression of vibration of the foundations leads to attenuation of sound radiation in the far-field induced by the radial displacement dominant mode of the shell. Moreover, vibration suppression is greatly influenced by the strong couplings among control channels. According to these results, it can be concluded that the proposed method is effective in the analysis of underwater sound radiation control of cylindrical structures.

Active vibration isolation and underwater sound radiation control

2008 ◽  
Vol 318 (4-5) ◽  
pp. 725-736 ◽  
Author(s):  
Zhiyi Zhang ◽  
Yong Chen ◽  
Xuewen Yin ◽  
Hongxing Hua
Keyword(s):  
Vibration Isolation ◽  
Sound Radiation ◽  
Underwater Sound ◽  
Radiation Control ◽  
Active Vibration ◽  
Active Vibration Isolation

Matching Design of Active Magnetic Bearing and Elastic Support Vibration Isolator

2020 ◽  
Author(s):  
Yichen Yao ◽  
Yixin Su ◽  
Tianye Yu ◽  
Gexue Ren ◽  
Suyuan Yu
Keyword(s):  
Frequency Domain ◽  
Vibration Isolation ◽  
Design Method ◽  
Rotating Machinery ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Vibration Isolators ◽  
Active Vibration ◽  
Matching Relation ◽  
Active Vibration Isolation

Abstract In modern industries, high-speed machinery occupies a fundamental place. However, rotating machinery will inevitably produce a variety of structural noise and vibration. Generally, vibration isolation means can be divided into active vibration isolation and passive vibration isolation, among which the most representative are active magnetic bearings (AMBs) and vibration isolators, respectively. The combination of active magnetic bearings and vibration isolators is widely used in rotating machinery because of its excellent effect in vibration and noise reduction. This paper concentrates on the analysis of the vibration transmission mechanism of the active magnetic bearings coupled with the vibration isolators. A 30 kW prototype pump is taken as an example to help describe the research method. The model of the pump is first established. The stationary pump components and the rotor are respectively modeled through the finite element method and converted to substructure modal expression after low-order modal extraction. The bearing force is simplified to spring-dampers with equivalent stiffness and equivalent damping relating to the exciting frequency. The vibration isolators are simplified as three-dimensional spring-dampers. Based on the model, this paper then investigates the matching relation of the AMBs and the vibration isolators and proposes a dynamic vibration isolation design method for the rotor-AMBs-flexible support system. On the basis of the frequency-domain response of the original design, this design method gives the frequency-domain curves of the desired stiffness and damping of the suitable active vibration isolation, which can be used to guide the controller design of the AMBs and isolators selection. According to the design, we have done laboratory experiments on the prototype pump. The results show that the design method based on matching relation has good performance in vibration isolation.

The Test Scheme Research on Active Control of Coupled Vibration between the Multiple CNC Milling Machines and the Flexible Foundation

2011 ◽  
Vol 105-107 ◽  
pp. 664-667
Author(s):  
Qian Lin Peng ◽  
Yao Gang Li ◽  
Fu Dong Ma
Keyword(s):  
Vibration Isolation ◽  
Test Scheme ◽  
Test Model ◽  
Cnc Milling ◽  
Vibration Isolators ◽  
Pilot Scheme ◽  
Milling Machines ◽  
Active Vibration ◽  
Flexible Foundation ◽  
Active Vibration Isolation

Analysis of the study based on the Working principle of machine isolators-flexible foundation system which combines with multiple exciters and sensors, an MIMO active vibration isolation test model is constructed. In addition, the choice of system device and the distribution position of the vibration isolators and sensor are revealed and analyzed. Ultimately the Pilot scheme of the MIMO active vibration isolation Pilot scheme is confirmed.

scholarly journals Tilt Active Vibration Isolation Using Vertical Pendulum and Piezoelectric Transducer with Parallel Controller

2021 ◽  
Vol 11 (10) ◽  
pp. 4526
Author(s):  
Lihua Wu ◽  
Yu Huang ◽  
Dequan Li
Keyword(s):  
Piezoelectric Transducer ◽  
Vibration Isolation ◽  
Vertical Vibration ◽  
Open Loop ◽  
Negative Effects ◽  
Voltage Controller ◽  
Hysteresis Nonlinearity ◽  
Passive Vibration Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

Tilt vibrations inevitably have negative effects on some precise engineering even after applying horizontal and vertical vibration isolations. It is difficult to adopt a traditional passive vibration isolation (PVI) scheme to realize tilt vibration isolation. In this paper, we present and develop a tilt active vibration isolation (AVI) device using a vertical pendulum (VP) tiltmeter and a piezoelectric transducer (PZT). The potential resolution of the VP is dependent on the mechanical thermal noise in the frequency bandwidth of about 0.0265 nrad, which need not be considered because it is far below the ground tilt of the laboratory. The tilt sensitivity of the device in an open-loop mode, investigated experimentally using a voltage controller, is found to be (1.63±0.11)×105 V/rad. To compensate for the hysteresis nonlinearity of the PZT, we experimentally established the multi-loop mathematical model of hysteresis, and designed a parallel controller consisting of both a hysteresis inverse model predictor and a digital proportional–integral–differential (PID) adjuster. Finally, the response of the device working in close-loop mode to the tilt vibration was tested experimentally, and the tilt AVI device showed a good vibration isolation performance, which can remarkably reduce the tilt vibration, for example, from 6.0131 μrad to below 0.0103 μrad.

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