The Influence of Piping Arrangement on the Response of Vibration Isolation System Under Underwater Explosion Loading

2019 ◽  
Author(s):  
Chen Pan ◽  
Wei Qiang ◽  
Liu Zhizhong ◽  
Wang Guan
Keyword(s):  
Shock Loading ◽  
Vibration Isolation ◽  
Underwater Explosion ◽  
Mechanical Equipment ◽  
Piping System ◽  
Flexible Pipe ◽  
Isolation System ◽  
Floating Raft ◽  
Shock Resistance ◽  
Actual Response

Abstract The response of ship equipment under non-contact underwater explosion shock loading was one of the main loadings of equipment. In order to cut down mechanical noise caused by mechanical equipment, vibration isolation measures, such as floating raft, vibration isolation, were widely used on noise mechanical equipments in acoustical stealth of ship, vibration isolation can reduce the vibration transfer to install base effectively, while the anti-shock resistance of vibration isolation and the equipment was important synchronously, as for the response of the equipment on vibration isolation, especially the actual response of the vibration isolation with piping system under shock loading. In this paper, the research on the response of vibration isolation, equipment, flexible piping and piping under underwater explosion shock loading were considered together, and the response of vibration isolation under shock load was analyzed with different piping arrangement. Found that the piping system has a significant impact on the response of the equipment under horizontal impact, but almost all equipments were assessed in experiment without considering the piping system. With the precondition of the effect of vibration isolation, a more rigid flexible pipe can be taken was benefit to the anti-shock resistance of vibration isolation.

The Vibration Isolation Effect Research of the Floating Raft Isolation System Based on the Adjustable Flexibility of Foundation

2013 ◽  
Vol 819 ◽  
pp. 115-119 ◽  
Author(s):  
Hui Wang ◽  
Ze Yu Weng ◽  
Gan Xiang ◽  
Bo Lu ◽  
Hong Gang Ding ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Test System ◽  
Isolation Effect ◽  
Isolation System ◽  
Elastic Beams ◽  
Floating Raft ◽  
Marine Engineering ◽  
Flexible Foundation ◽  
The Relationship ◽  
Theoretical Results

The floating raft isolation system is widely used in the field of marine engineering for its vibration isolation effect. Along with the application of light thinning structure of the ship, the flexibility of foundation of floating raft isolation system makes the vibration isolation effect vary widely between the practical floating raft isolation system and its theoretical results. In order to research the vibration isolation effect of the floating raft isolation system on different flexibility of foundation, the floating raft isolation system with flexible foundation is designed in this paper, and the adjustable flexibility of foundation is achieved by using elastic beams. With simulation and analysis of test system in ADAMS, the results of the relationship between flexibility and vibration isolation effect are obtained.

Study on Floating Raft Vibration Isolation System for Pumping Unit

2011 ◽  
Vol 383-390 ◽  
pp. 130-135 ◽  
Author(s):  
Fu Mao Wang ◽  
Chang Guo Wang ◽  
Lan Lan Guo ◽  
Bang Chun Wen ◽  
Yong Li
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Vibration Isolation ◽  
Steel Structure ◽  
Elastic Cylinder ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Floating Raft ◽  
Pumping Units ◽  
Important Basis

In this paper, based on the theory of double layered vibration isolation, the finite element dynamic model of floating raft vibration isolation system has been established for the project of vibration and noise control in a heat exchange station. The dynamic model of single pump is simplified an elastic cylinder based on the principle of equivalent parameters, and the elastic raft frame is used of steel structure. The dynamic characteristics of the system is analyzed by used of ANSYS with SOLID45 unit and COMBIN14 spring-damper unit, which provide an important basis for the engineering design of floating raft isolation system with pumping units.

Theory and Method of Dynamic Modeling for Multilayer Vibration Isolation System

2000 ◽  
Author(s):  
Liao Dao-Xun ◽  
Lu Yong-Zhong ◽  
Huang Xiao-Cheng
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Vibration Isolation ◽  
Rigid Bodies ◽  
Design Calculation ◽  
Isolation System ◽  
Dry Land ◽  
Vibration Isolation System ◽  
Six Degrees Of Freedom ◽  
Floating Raft

Abstract The multilayer vibration isolation system has been widely applied to isolate vibration in dynamic devices of ships, high-speed vehicles forging hammer and precise instruments. The paper is based on the coordinate transformation of space general motion for mass blocks (rigid bodies) and Lagrangian equation of multilayer vibration isolation system. It gives a strict mathematical derivation on the differential equation of the motion for the system with six degrees of freedom of relative motion between mass blocks (including base). The equations are different from the same kind of equations in the reference literatures. It can be used in the floating raft of ships in order to isolates vibration and decrease noise, also used in design calculation of the multilayer vibration isolation for dynamic machines and precise instruments on the dry land.

Force transmissibility of floating raft systems with quasi-zero-stiffness isolators

2017 ◽  
Vol 24 (16) ◽  
pp. 3608-3616 ◽  
Author(s):  
Li Yingli ◽  
Xu Daolin
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Low Frequency ◽  
Frequency Region ◽  
Mass Ratio ◽  
Isolation System ◽  
Floating Raft ◽  
Highly Nonlinear ◽  
Vibration Attenuation ◽  
Force Transmissibility

In view of the excellent performance of a single quasi-zero-stiffness (QZS) device in vibration attenuation, this paper presents a study on a vibration isolation floating raft system constructed with a double-layer QZS mechanism. A QZS device is a typical nonlinear isolator, hence the floating raft system is a coupled highly nonlinear isolation system. To understand the behaviors and its performance in vibration attenuation, an analytical approach is developed to describe the characteristics including the mathematical relationship between amplitude–frequency, force transmissibility, and the effects of the mass ratio and damping ratios on attenuation performance. The outcomes show that the two-degree-of-freedom QZS–QZS system is superior for vibration isolation when compared to the traditional linear system and the two other types of QZS systems. The effective vibration isolation frequency region of the QZS–QZS system is expanded to the low-frequency region by 72%. The QZS system is sensitive to the damping ratio, which decreases the resonance peak significantly. The mass ratio is a crucial design parameter in low-frequency vibration isolation design.

scholarly journals H∞ active control of frequency-varying disturbances in a main engine on the floating raft vibration isolation system

2017 ◽  
Vol 37 (2) ◽  
pp. 199-215 ◽  
Author(s):  
Chunsheng Song ◽  
Yao Xiao ◽  
Chuanchao Yu ◽  
Wei Xu ◽  
Jinguang Zhang
Keyword(s):  
Numerical Simulation ◽  
Vibration Isolation ◽  
Control Method ◽  
Mimo System ◽  
Single Frequency ◽  
Isolation System ◽  
Floating Raft ◽  
Power Machinery ◽  
Simulation Results ◽  
Dominant Frequencies

Reducing the vibration of marine power machinery can improve warships' capabilities of concealment and reconnaissance. Being one of the most effective means to reduce mechanical vibrations, the active vibration control technology can overcome the poor effect in low frequency of traditional passive vibration isolation. As the vibrations arising from operation of marine power machinery are actually the frequency-varying disturbances, the H∞ control method is adopted to suppress frequency-varying disturbances. The H∞ control method can solve the stability problems caused by the uncertainty of the model and reshape the frequency response function of the closed loop system. Two-input two-output continuous transfer function models were identified by using the system identification method and are validated in frequency domain of which all values of best fit exceeds 89%. The method of selecting the weighting functions on the mixed sensitivity problem is studied. Besides, the H∞ controller is designed for a multiple input multiple output (MIMO) system to suppress the single-frequency-varying disturbance. The numerical simulation results show that the magnitudes of the error signals are reduced by more than 50%, and the amplitudes of the dominant frequencies are attenuated by more than 10 dB. Finally, the single excitation source dual-channel control experiments are conducted on the floating raft isolation system. The experiment results reveal that the root mean square values of the error signals under control have fallen by more 74% than that without control, and the amplitudes of the error signals in the dominant frequencies are attenuated above 13 dB. The experiment results and the numerical simulation results are basically in line, indicating a good vibration isolation effect.

Parameters Performance to the Vibration Isolation in Three-Dimensional Elastic Floating Raft Isolation System

2012 ◽  
Vol 472-475 ◽  
pp. 2659-2662 ◽  
Author(s):  
Guo He Jiang ◽  
Gang Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Vibration Isolation ◽  
Three Dimensional ◽  
Vibration Response ◽  
System Model ◽  
The Finite Element Method ◽  
Isolation System ◽  
Floating Raft ◽  
Element Method

Based on the three-dimensional elastic floating raft isolation system model, this paper using the finite element method to calculate vibration response of the system, and then analyze the performance of floating raft under different mass and stiffness, providing useful conclusions for vibration isolation designing.

System Optimal Design Based on Neighborhood Cultivation Genetic Algorithm Combined with Modified Method of Feasible Directions

2010 ◽  
Vol 143-144 ◽  
pp. 980-983
Author(s):  
Lu Wang ◽  
Cun Sheng Zhao
Keyword(s):  
Optimization Design ◽  
Vibration Isolation ◽  
Optimization Techniques ◽  
Modified Method ◽  
Floating Raft ◽  
Design Variables ◽  
Pareto Sets ◽  
Resistance System ◽  
Shock Resistance ◽  
Set Up

Parametric model of floating raft vibration isolation and shock resistance system was built. Optimization techniques of exploitation combined with exploration was brought forward with NCGA used in global and MMFD used in local optimization. Multi-objective optimization design frame was set up in the paper and the Pareto optimal sets were given. At last the method of deducing design variables from Pareto sets was brought forward.

Optimization Design of Vibration and Shock Isolation System

2006 ◽  
Author(s):  
Cun-Sheng Zhao ◽  
Shi-Jian Zhu ◽  
Zhen-Zhong Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Vibration Isolation ◽  
Design Method ◽  
Engineering Application ◽  
Experimental Results ◽  
Isolation System ◽  
Combination Optimization ◽  
Shock Resistance ◽  
Shock Isolation

The combination optimization design problem of vibration isolation and shock resistance system is studied in consideration of acoustical concealment performance and lifeforce of ships. The weakness of design method based on continuity is pointed out and combination optimal design method is brought forward. Then the limiting performance of shock isolation system is analyzed and two realization methods are discussed. One method is to adopt linear stiffness component with large damping. The other method is to use multiple linear stiffness components without damping. Amplitude of steady excitation is much smaller than that of shock input during experiment. Experimental results showed that the optimal loss factor is still 0.4 when the stiffness of shock bumper is much larger than that of vibration isolator, just the same with that suffered from only shock loads. Experimental results also showed that limiting performance can be achieved by configuration optimal design using multiple linear components. The two discussed methods can be used to direct engineering application.

Research on the Effect of Load on the Fatigue Tearing of the Elastic Element

2013 ◽  
Vol 753-755 ◽  
pp. 1836-1841
Author(s):  
Zheng Tao Yan ◽  
Wen Wu Liu ◽  
Hai Feng Li
Keyword(s):  
Elastic Element ◽  
Vibration Isolation ◽  
Engineering Practice ◽  
Ansys Software ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Crack Location ◽  
Floating Raft ◽  
Strain Change ◽  
Rubber Isolator

According to engineering implement, the elastic element of the rubber isolator is easy prone to fatigue tearing, the model of the pump group floating raft vibration isolation system is established by ADAMS and the finite element ANSYS software, the force distribution of the system is calculated in the different swing angles in ADAMS, and the main reason of the elastic element fatigue tearing is found. Then, the strain change rule of the elastic element is researched in ANSYS, the elastic element which is the most vulnerable to fatigue tearing and its crack location are found, which plays an important role in solving the fatigue tearing of the rubber elastic element in the engineering practice.

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