scholarly journals Vibration Protection of Sensitive Components of Infrared Equipment in Harsh Environments

2001 ◽  
Vol 8 (1) ◽  
pp. 55-69 ◽  
Author(s):  
A.M. Veprik ◽  
V.I. Babitsky ◽  
N. Pundak ◽  
S.V. Riabzev
Keyword(s):  
Vibration Isolation ◽  
Harsh Environments ◽  
Line Of Sight ◽  
Infrared Sensor ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Vibration Protection ◽  
Electro Optic ◽  
Environmental Vibration

This article addresses the principles of optimal vibration protection of the internal sensitive components of infrared equipment from harsh environmental vibration. The authors have developed an approach to the design of external vibration isolators with properties to minimise the vibration-induced line-of-sight jitter which is caused by the relative deflection of the infrared sensor and the optic system, subject to strict constraints on the allowable sway space of the entire electro-optic package. In this approach, the package itself is used as the first-level vibration isolation stage relative to the internal highly responsive components.It was predicted analytically, and confirmed experimentally, that the proposed vibration isolation system would be capable of a sixfold reduction of the dynamic response of the infrared sensor as compared to the case of rigid mounting of the entire package.

A Variable Stiffness Vibration Isolation System Based on Magneto-Rheological Elastomer

2012 ◽  
Vol 452-453 ◽  
pp. 659-662
Author(s):  
Wei Wang ◽  
Yi Min Deng
Keyword(s):  
Shear Modulus ◽  
Vibration Isolation ◽  
Variable Stiffness ◽  
Control Area ◽  
Frequency Range ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Magneto Rheological ◽  
Conventional Type

Vibration isolation is a most widely used vibration protection method.The stiffness of vibration isolators in existing conventional type of vibration isolation system is usually of fixed value. This limits the system in exhibiting its vibration isolation effect in that, it has poor results for lower frequency vibration, especially for resonance frequency. Magneto-rheological elastomer is a new branch of Magneto-rheological materials. It’s an intelligent materials in that it’s shear modulus can be controlled by a magnetic field. It has wide application prospects in the vibration control area. This paper proposes using adjustable stiffness of magneto-rheological elastomer vibration isolation in vibration isolation system. By changing the current of vibration isolators coil to control the shear modulus of magneto-rheological elastomer, it can adjust the stiffness of the isolation system, making the system obtain wider vibration isolation frequency range. By exploying SimuLink software to analyze the vibration isolation system, it is found that such a design is effective and applicable.

scholarly journals Reconstruction of Input Excitation Acting on Vibration Isolation System

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Pan Zhou ◽  
Wen L. Li ◽  
Wanyou Li ◽  
Zhijun Shuai
Keyword(s):  
Vibration Isolation ◽  
Mechanical Design ◽  
Spectral Density Function ◽  
Dynamic Responses ◽  
Accurate Estimation ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Supporting Structure ◽  
Vibration Prediction

Vibration isolation systems are widely employed in automotive, marine, aerospace, and other engineering fields. Accurate input forces are of great significance for mechanical design, vibration prediction, and structure modification and optimization. One-stage vibration isolation system including engine, vibration isolators, and flexible supporting structure is modeled theoretically in this paper. Input excitation acting on the vibration isolation system is reconstructed using dynamic responses measured on engine and supporting structure under in-suit condition. The reconstructed forces reveal that dynamic responses on rigid body are likely to provide more accurate estimation results. Moreover, in order to improve the accuracy of excitation reconstructed by dynamic responses on flexible supporting structure, auto/cross-power spectral density function is utilized to reduce measurement noise.

Dynamic Analysis of Nonlinear Vibration Isolation System Based on Flexible Foundation

2014 ◽  
Vol 1030-1032 ◽  
pp. 766-769
Author(s):  
Shu Ying Li ◽  
Rui Huo ◽  
Xing Ke Cui ◽  
Cui Ping Liu ◽  
Dao Kun Zhang
Keyword(s):  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Coupled System ◽  
Optimized Design ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Flexible Foundation

In this paper,a general dynamic model of the isolation coupled system which is composed of isolation object,nonlinear vibration isolation support,and flexible foundation is established,calculated method of applying vibration power flow to analyze isolation effectiveness is studied.Further more,as an calculation example,a air spring vibration isolation system of HS-700 engines is numerically simulated.Designs several low-frequency nonlinear vibration isolators and analyzes its vibration isolation effect.It discusses the effect of the vibration isolator parameters on the transmitted power flow of the system.The results provide a theoretical basis for the optimized design of nonlinear vibration isolation system.

STUDY OF THE VIBRATION ISOLATION SYSTEM OF MARINE POWER PLANTS WITH A 5AL 25/30 DIESEL DRIVE

Akustika ◽  
2021 ◽  
pp. 112
Author(s):  
Minas Minasyan ◽  
Armen Minasyan ◽  
Kyaw Thet Naing
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Power Plants ◽  
Vibration Isolation ◽  
Field Studies ◽  
Absorption System ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
The Impact

The article is devoted to the study of the support and side stop vibration isolation system of two marine power plants DGA- 500 with a 5AL 25/30 drive diesel engine, in which a hypothesis is put forward about the imperfection of the shock absorption system. The purpose of the research is to substantiate the imperfection of the support and side stop vibration isolation system of marine power plants with a 5 AL 25/30 drive diesel engine. The confirmation of this hypothesis and the achievement of this goal is justified on the basis of presentation of the results of field studies on the project’s courts B437/11 and the personal presence during the preparation of DGA-500 to repair at the shipyard. For the use of unbalanced engines as a drive for ship power plants, the authors, on the basis of a full-scale experimental study and analysis of known works, recommend initially assessing the possibility and purpose of depreciation of the unit according to the Katz unbalance criterion [1]. The objective of fixing the unit with diesel 5AL 25/30 on the criterion of imbalance Katz is soundproof, and the calculation of depreciation should be based on the impact of side stop vibration isolators. A significant improvement is recommended to the support 36-40 and side stop 41-52 vibration isolation system, elastic pipe fittings 8, support frame 2 and turbocharger bracket 4 (Fig. 1).

scholarly journals Design Methodology of a Passive Vibration Isolation System for an Optical System With Sensitive Line-of-Sight

2021 ◽  
Author(s):  
Keqi Qi ◽  
Lei Dai ◽  
Shaoxin Wang ◽  
Yongming Yang ◽  
Yalin Ding ◽  
...  
Keyword(s):  
Optical System ◽  
Design Methodology ◽  
Vibration Isolation ◽  
Installation Space ◽  
Line Of Sight ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Passive Vibration Isolation ◽  
Rotational Vibration ◽  
Sensitive Line

AbstractThe performance of an optical system with sensitive line-of-sight (LOS) is influenced by rotational vibration. In view of this, a design methodology is proposed for a passive vibration isolation system in an optical system with sensitive LOS. Rotational vibration is attributed to two sources: transmitted from the mounting base and generated by modal coupling. Therefore, the elimination of the rotational vibration caused by coupling becomes an important part of the design of the isolation system. Additionally, the decoupling conditions of the system can be obtained. When the system is totally decoupled, the vibration on each degree of freedom (DOF) can be analyzed independently. Therefore, the stiffness and damping coefficient on each DOF could be obtained by limiting the vibration transmissibility, in accordance to actual requirements. The design of a vibration isolation system must be restricted by the size and shape of the payload and the installation space, and the layout constrains are thus also discussed.

scholarly journals Protection of precision spacecraft equipment from internal sources of vibration

2021 ◽  
Vol 5 (4) ◽  
pp. 217-226
Author(s):  
Yu. A. Zhukov ◽  
E. B. Korotkov ◽  
S. A. Matveev ◽  
N. S. Slobodzyan ◽  
O. V. Shirobokov
Keyword(s):  
Vibration Isolation ◽  
Vibration Suppression ◽  
Thermal Control ◽  
Vibration Source ◽  
Electric Pump ◽  
Pump Unit ◽  
Isolation System ◽  
Vibration Isolators ◽  
Vibration Protection ◽  
Vibration Dampers

The work is devoted to the protection of a spacecraft from the influence of unacceptable internal vibration sources. The urgency of reducing the vibration activity on board the spacecraft to improve the accuracy of the target equipment is indicated. A particular problem of vibration protection of the spacecraft platform from a vibration source – an electric pump unit of a liquid thermal control system – is being solved. The basic requirements for electric pump unit vibration protection have been determined. Possible ways to reduce the level of vibration excited by the electric pump unit on the surface of the spacecraft fixation are considered. Particular attention is paid to such vibration protection methods as damping and vibration isolation, implemented by installing special vibration protection devices between the source (electric pump unit) and the object (spacecraft) – vibration isolators and vibration dampers. The principles of operation of vibration dampers and vibration isolators, the most common materials for vibration dampers are described. Examples of constructive solutions for linear single-axial vibration isolators are considered, recommendations for the use of promising products are developed. Particularemphasis is placed on the use of metal rubber as a material for vibration isolators. With regard to a specific design of electric pump unit, a diagram of the spatial structure of vibration isolation is proposed. Formulas for calculation are given in detail, a mathematical model of the vibration isolation system is developed. The procedure for calculating the parameters of the system has been formed. Based on the model, the maximum possible level of vibration suppression in the mid-frequency region was determined. Minimum required number of operable pixels was identified for monitoring the water surface with sufficient accuracy and reliability.

scholarly journals Indirect Control of Oscillations: Elements of Theory

2018 ◽  
Vol 18 (1) ◽  
pp. 148-175
Author(s):  
Vladimir Chernyshev ◽  
Leonid Savin ◽  
Olga Fominova
Keyword(s):  
Vibration Isolation ◽  
Dynamic Properties ◽  
Harmonic Balance Method ◽  
Frequency Region ◽  
Optimal Sequence ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Basic Model ◽  
Indirect Control ◽  
Vibration Protection

A brief review of the main research areas in the field of controlled vibration protection systems is given. It is shown that Vibration systems with indirect control processes of oscillations allow with a minimum expenditure of energy to ensure programmable switching parameters and structures, in which the dissipative restoring and inertial forces generated on the basis of active impact. Within synthesis of indirect control the chains of new auxiliary mathematical constructs for finding optimal synthesizing functions of the elastic-damping units parameters control are obtained. It enabled to separate a base model with intermittent damping and base model with impulse trap. As a result of the study, based on the harmonic balance method, the dynamic properties of the basic model with intermittent damping, calculation formulas are obtained for determining the parameters of the compensation effect and calculating the dynamic coefficient. It is established that, with an optimal sequence of damping switching, the resonant phenomena are eliminated, and the transient processes decay within one period of the kinematic perturbation. The basic model with a pulse trap imitates the limiting variant of intermittent damping and realizes the process of superimposing constraining bonds, the sequence and duration of which are new variables essentially increasing controllability. And for indirect pulse control, there exicts a certain minimum of power consumption independent of the achieved effect of vibration protection. A regulated increase in the duration of the application of the restraining coupling in the low-frequency region and a decrease in this duration in the high-frequency region provides a monotonically decreasing dependence on the dynamic coefficients over the entire frequency range. An example of a solution to the optimization problem of controlling the damping process for a basic model of a vibration isolation system is considered. It is established that intermittent damping is an indispensable feature of the optimality of the vibration isolation system: the damper switches on when the sign of the object's speed has changed and turns off when the object's displacement sign has changed.

Vibration Isolation

2021 ◽  
pp. 299-312
Author(s):  
C. Julian Chen
Keyword(s):  
Eddy Current ◽  
Vibration Isolation ◽  
Mechanical Design ◽  
Two Stage ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Suspension Spring ◽  
Environmental Vibration ◽  
Eddy Current Damping ◽  
Elementary Mechanics

This chapter discusses vibration isolation of STM and AFM. First, the basic concepts of vibration isolation are illustrated by a one-dimensional system using elementary mechanics. The source of vibration, the environmental vibration, its characteristics, and methods of measurement are presented. The importance of vibration isolation at the laboratory foundation level and the proper mechanical design of STM and AFM are then discussed. The focus of this chapter in on the most important vibration isolation system: two-stage suspension spring with eddy-current damping. A detailed analysis of the two-stage spring system as well as aspects of practical design is presented. The principles and design charts for eddy-current damping system are discussed. Finally, the commercial pneumatic vibration isolation system is briefly discussed.

A New Method for the Optimization of a Vibration Isolation System

1990 ◽  
Vol 112 (3) ◽  
pp. 413-416 ◽  
Author(s):  
Y. Lin ◽  
W. Luo ◽  
Y. M. Zhang
Keyword(s):  
Optimal Control ◽  
Vibration Isolation ◽  
High Efficiency ◽  
High Reliability ◽  
Vibration Isolator ◽  
Reliability Of Results ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Programming Algorithms

Formerly the optimization of the passive vibration isolator is mainly founded on the nonlinear programming algorithms. The methods are iterative in nature and time-consuming. In this paper a frequency domain suboptimal method is developed for the optimization of the passive vibration isolators. The method is based on the linear optimal control results and has advantages of high efficiency in computation and high reliability of results. It is especially applicable to the microcomputer environment.

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