Vibration Protection Research Articles

Some issues of improving the accuracy of the system configuration of the vibration with inertial converter

In this work considered issues of elastic and dissipative characteristics for vibration protection systems with inertial conventer. Represenred the results of numerical simulation with taking account of the proposed. The condition for setting the frequency offset is determined and ways to improve the effectiveness of vibration protection are proposed.

Vibration protection drive control in small movement mode

Mathematical model of the stepper motor is considered. Features of “large” and “small” movements require implementation different approaches to solve stabilization problem. For large movements, is proposed to use an algorithm of active regulation according information from position sensor. Small movements, stabilization algorithm is proposed taking into account use elastic-dissipative properties of the creation and control stopping torque.

Transmission of Railway Induced Vibrations in Buildings

This paper presents the problem of vibration transmission in building structures, which is induced by rail transport, and it discusses the effect of acoustic isolation used at the foundation. The vibration sources generate acoustic waves which are transmitted to the foundation and propagate trough the floors and slabs of the building. The transmission coefficients of the acoustic waves induced by metro trains and trams were determined in the building foundation and slabs. It was shown that mechanical resonances have a significant influence on the vibrations of the slabs. The characteristics of vibration propagation through vibration-insulated floors were found. Using the data obtained in this study, vibration effects in buildings located near vibration sources can be estimated, vibration protection measures can be developed.

Vibration Protection Model of Pumped-storage Unit Based on Inverse-time Method

Vibration Protection Model of Pumped-storage Unit Based on Inverse-time Method

СИСТЕМА ВИБРОЗАЩИТА С УПРУГИМ ЗВЕНОМ ПРЕРЫВИСТОГО ДЕЙСТВИЯ КОНСТРУКТИВНЫЕ РЕШЕНИЯ И ИХ ОПРОБАЦИЯ

The article considers a vibration protection system with an elastic intermittent link. A constructive solution is presented in the form of a mechanical oscillator simulating the process of operation of the considered vibration protection system. The results of experimental studies of the operation of a mechanical oscillator are presented. Conclusions have been drawn on the prospects of using a vibration protection system with an intermittent elastic link.

The experimental method for testing relaxation of pneumatic elements with a rubber-cord casing

The method for the experimental study of the viscoelastic properties of pneumatic elements with a rubber-cord casing is proposed. Based tests of relaxation in which the height of the pneumatic element is kept constant (a practically incompressible fluid is used as the working medium). The implementation of the method is illustrated by the example of the rubber-cord casing of the balloon type of model N-50. The value of the absorption coefficient (relative hysteresis) is established, which in order of magnitude coincides with the value of the absorption coefficient of tread rubbers given in literary sources. In the process of holding the height of the pneumatic element at a constant level, increments of the force of the pneumatic element and overpressure are proportional to each other with a proportionality coefficient depending on the value of the internal volume and height of the air element. The comparative analysis of the features of the operation of pneumatic elements in cases where the working medium is a gas or liquid is done. The results obtained are of interest in the development of vibration protection and vibration isolation systems for technical objects, the design of which includes air springs, air damping shock absorbers and rubber-hydraulic vibration mounts.

The experimental method for determining the geometric characteristics of pneumatic elements with rubber-cord casing

The method for experimentally constructing the geometric characteristics of pneumatic elements with rubber-cord casing at zero and quasi-zero pressure is proposed. The practical implementation of the method by the example of the rubber-cord shell of the balloon type of model N-50 is illustrated. The processed experimental data in an analytical form presents the empirical dependences of the internal volume on the height of the pneumatic element at zero and quasi-zero overpressure. The obtained parameters are mandatory for the model of air spring and study the damping phenomenon. The results obtained are intended for the development of vibration protection and vibration isolation systems for technical objects, the design of which includes air springs and air damping shock absorbers.

Исследование эффективности электромеханической системы активной виброзащиты автомобиля с различными регуляторами

Исследование эффективности электромеханической системы активной виброзащиты автомобиля с различными регуляторами

СОВЕРШЕНСТВОВАНИЕ СТАНОЧНОГО ОБОРУДОВАНИЯ ДЛЯ ПРЕЦИЗИОННОЙ ОБРАБОТКИ ДЕТАЛЕЙ В ПЛАВУЧИХ МАСТЕРСКИХ

The article discusses the results of research and development in the direction of improving machine equipment for precision machining of parts in the conditions of floating workshops by increasing the vibration resistance of the technological system and reducing the harmful effects of the external environment (sea waves) and neighboring operating equipment The traditional vibration–isolating supports of the machines cannot be used at floating workshops due to their loss of functioning under the rolling pitch of the floating base and horizontal displacements under its influence. New effective design variants of the vibration protection device of precision machine tools and supports with active vibration isolation are described, which allow automatic control of the damping of the machine vibration–isolating support under external influences.

Assessment of Rail Vibration Transmission from the Ground to the Foundation of a Building

This paper presents the problem of rail transport vibration transmission from the ground to building foundations. Field measurement results of vibration parameters on the ground near buildings and their foundations have been covered in this study. It has been shown that vibrations at the foundation of a building are much smaller than vibrations on the ground. The most intense vibrations on the foundation slab occur in the vertical direction. Comparison with other experimental data on vibration transfer from the ground to buildings structures has been made. The data obtained can be utilized in designing vibration protection measures and to analytically predict vibration effects in buildings. This analysis can be performed after measuring the vibration of rail transport on the ground surface.

The experimental method for determining the isobaric power characteristics of pneumatic elements with rubber-cord casing

A method for the experimental construction of isobaric static (equilibrium) power characteristics of pneumatic elements with a rubber-cord casing at a constant temperature is proposed. This method also allows you to determine isobar geometric characteristics, establishing a relationship between the height of the pneumatic element and the increment of its internal volume relative to some fixed position. The practical implementation of the method is illustrated by the example of a pneumatic element with a rubber-cord casing of the balloon type of the model N-50. The agreement of the experiment with the theoretical data calculated by the traditional method, widely used in the scientific literature, is analyzed. The obtained parameters are mandatory for the model of air spring and study the damping phenomenon. The results of the study are intended to develop vibration protection and vibration isolation systems for technical objects, the design of which includes air springs and air damping shock absorbers.

ДИНАМИКА ВИБРОЗАЩИТНЫХ СИСТЕМ С УПРАВЛЯЕМЫМ МЕХАНИЗМОМ НАЛОЖЕНИЯ СВЯЗЕЙ

In the paper there are presented the applied theory elements of new basic models of vibration-proof systems with additional controlled devices of intermittent functioning – a mechanism of connection imposition and a pulse trap. 
 The ultimate options of control resulting in jumping changes of a system structure when control occasionally increases sharply and becomes a zero result. The sequential alternation of control data defines so-called an indirect pulse control of the parameters of damping and stiffness of an additional (controlled) elastic-damping link of intermittent action. At that, irrespective of the type of the controlled links used, such as a damper of viscous resistance, a friction damper or elastic damper the achieved effect of vibration protection under all other equal conditions will be equal. 
 These controlled links imitate the operation of connection imposition mechanism, that is, they block occasionally a vibration protection system that allows improving considerably its dynamic properties at the expense of a new parameter defining the length of such blocks. In particular, it is possible to consider also the imitation of the operation of a pulse trap realizing instant (pulse) blocks of the system as a result of which the rate of the object protected is occasionally zero.
 Basic investigation results of dynamic properties of these systems:
 - Resonance phenomena are eliminated (in steady-state oscillation modes of the object oscillation decrease monotonously with the frequency increase of kinematic harmonic disturbance);
 - Transients caused by initial conditions or random fluctuations of external disturbances damp within the limits of one period of impact, that is, the process is carried out which is characterized as “one shock – one oscillation”; 
 - System invariance with respect to power disturbances as a result of periodic blockings increases considerably and, as a consequence it is possible to decrease the stiffness of a bearing elastic component without fear for stability loss; 
 - Energy costs for realization of indirect pulse control are connected only with the “switch on-switch off” process which may be programmed through components of the system state in a relative motion by means of the actualization of system design properties.

DEVELOPMENT OF VIBRATION PROTECTIVE TECHNOLOGIES BASED ON THE MR (METALLIC RUBBER) MATERIAL FOR RUSSIAN LOCOMOTIVES

The article describes the use of the elastic-porous damped wire material MR for solving the problems of ensuring vibration safety when creating locomotives of a new generation. Vibration isolators made of MR material for railway diesel generators and the vibration protection system of the drivers cabin of the TEM-28 locomotive are considered.

Seismic and shock effects reduction by vibration protection systems equipped with amplifiers of inertial characteristics

The article considers the issue of reducing the impact pulse on an object by creating an energy absorber on the pulse distribution path, using the increasing additional inertia principle in relative motion.

Study of longitudinal vibrations of stab knife refiners

The subject of research is the longitudinal vibrations of stab knife refiners. A model of the fibrous layer between the rotor and stator is developed. It is shown that it is advisable to use the Maxwell-Thomson model for liquid friction of the rotor and stator, and the Hooke elastic model for boundary friction. The formula for determining the dynamic stiffness of the fibrous layer is obtained. Dynamic and mathematical models of the refiner in the longitudinal direction are developed. The mathematical model is a system of linear differential equations with periodically varying coefficients (Mathieu-Hill equations). A method for calculating the amplitude of oscillations of the refiner rotor and stator is developed. According to this technique, Andritz 54-60-1c stab refiner was designed. Oscillation parameters of the refiner rotor and stator are determined theoretically and experimentally. The stator oscillation amplitude is 1.6–2.3 times smaller than the rotor oscillation one. In case of boundary friction, the amplitude of oscillations of the stator and rotor increases by 2–3 times in comparison with liquid friction. The oscillation amplitude of the rotor and stator in the longitudinal direction is comparable with the gap between these elements. Therefore, it is recommended while designing refiners, to develop methods and means of vibration protection, and during operation, to prevent boundary friction between headsets. The developed calculation procedure can be used in other industries, for example, mining and metallurgy.

Design and Analysis of Coaxial Magnetic Gear Mechanism with Halbach Permanent-Magnet Array

The disadvantages of mechanical gear can be replaced by the advantages of magnetic gear related to transferring torque without mechanical touch, no gear lubrication, low mechanical loss, low vibration, and intrinsic overload protection. From the types of magnetic gear, coaxial magnetic gear is the most developed type. Halbach permanent-magnet arrangement in coaxial magnetic gear mechanism can offer higher on transmitted torque and also capable of increasing the magnetic field compared to radially magnetized. Then this paper aims to carry out the characteristic of coaxial magnetic gear with Halbach magnetized in steady-state condition. Furthermore, magnetic field and transmitted torque were investigated by commercial software ANSYS/Maxwell. Finally, by using 2D finite element method, the result shows the maximum torque with 2150.76 Nm.

On the Comprehensive Program of Vibration Protection of Precision Interplanetary Stations with Increased Requirements for Maintaining the Accuracy of Orientation

This paper is concerned with the issue of developing comprehensive programs of vibration protection of space structures for subsequent introduction into production in the rocket and space industries.

Introduction of additional inertial couplings in mathematical models of problems of vibration protection and vibration isolation

The article considers forced vibrations of a four-axle vehicle with a double spring suspension. The motion of a system with six degrees of freedom can be represented with sufficient accuracy by a system with two degrees of freedom. Therefore, the vehicle body has two degrees of freedom: lateral motion and wabbling, bouncing and pitching of trolleys will be neglected. The total number of degrees of freedom of the model is two. A method that leads to a closed solution for steady-state oscillations is considered. As a result of the research, differential equations of motion of the system were generated and an analytical solution was obtained for the case of application of an external piecewise constant driving force.

Airborne Laboratory for Gravity Field Research

Modern methods of studying the Earth’s gravity field on a mobile base are discussed, among them aerogravimetric research. The features of creating a highly autonomous airborne gravimetric laboratory with a long flight duration for operations in remote territories and waters are described. The experience of creating an airborne laboratory based on AN-30D and AN-26BL aircraft is discussed in detail. The makeup of gravimetric and navigation equipment is substantiated; the need for installing additional thermal and vibration protection devices, backup power lines, and additional communication facilities is shown; and the device and operation of airborne gravimetric systems based on different principles of operation are considered. The aerogravimetric survey method and features of its implementation are discussed. The main provisions of the software packages for in situ and office processing of gravimetric and navigation information obtained both on board the aircraft and at GPS or GLONASS base (ground) stations are presented. Methods for taking into account corrections for aerogravimetric systems with different operating principles are discussed.

Dynamic vibration protection of the railway carriage

The article describes the conditions under which the freight in the car is subject to force impact. The car has two degrees of freedom, and the freight has one. In the general case, if the system parameters satisfy the equation of the system, we have an antiresonance. In particular cases, if Н1 or Н2 or Н3 is zero, the antiresonance mode occurs when conditions are met, respectively. In these cases, the freight is at rest, which is often required to preserve the freight during transportation by rail. The conditions for dynamic damping of freight oscillations are obtained.