Mathematical Model of the Dynamics in a One Nonholonomic Vibration Protection System

This paper overviews the main results obtained over the past few years at the Department of Hydromechanical Systems Dynamics and Vibration Protection Systems, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, in the solution of current problems in the dynamics of liquid-propellant rocket engines (LPREs), liquid-propellant launch vehicle pogo stability, vibration protection system dynamics, the gas dynamics of aircraft gas turbine engine components, and the dynamics of hydraulic systems with cavitating elements. These results are as follows. A mathematical model of LPRE pump dynamics was developed. The model complements a hydrodynamic model of LPRE cavitating pumps by allowing a mathematical simulation of choking regimes. An approach was developed to the construction of a nonlinear mathematical model of LPRE hydraulic line filling. The approach allows one to automatically change, if necessary, the finite element partitioning scheme of a hydraulic line in the process of its filling during LPRE startup calculations. An investigation was conducted into the startup dynamics of a multiengine liquid-propellant propulsion system that consists of four staged-combustion oxidizer-rich LPRDs with account for the possibility of their nonsimultaneous startup. The maximum values of oxidizer and fuel pressure surges and undershoots at the liquid-propellant jet system (LPJS) inlet at an engine spartup and shutdown were determined and used in determining the LPJS operability at the startup and shutdown of the RD861K sustainer engine. The pogo stability of the Cyclone-4M launch vehicle was analyzed analytically using Nyquist’s criterion. A numerical approach was developed to characterizing acoustic oscillations of the combustion products in annular rocket combustion chambers with account for the configuration features of the fire space and the variation of the physical properties of the gaseous medium with the axial length of the chamber. A prototype vibration protection system was developed and made, and its dynamic tests confirmed its high efficiency in damping impact and harmonic disturbances. Approaches were developed to the aerodynamic improvement of aircraft gas turbine engine components. Topical problems in solids grinding in a liquid medium with the use a cavitation pulse technology were solved.

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Simulation model of a chair vibration protective mechanism with a part of quasi-zero-stiffness for the operator of a road-building machine

Nauchno-tekhnicheskiy vestnik Bryanskogo gosudarstvennogo universiteta ◽

10.22281/2413-9920-2020-06-04-486-496 ◽

2020 ◽

Vol 6 (4) ◽

pp. 486-496

Author(s):

M.S. Korytov ◽

◽

V.S. Sherbakov ◽

I.E. Pochekueva ◽

◽

...

Keyword(s):

Mathematical Model ◽

Vibration Isolation ◽

Degree Of Freedom ◽

Protection System ◽

Production Factor ◽

Protective Mechanism ◽

Static Force ◽

Vertical Movements ◽

Vibration Protection ◽

Protection Systems

Vibrations of construction and road machinery components that occur during their operation are a harmful production factor for machine operators, therefore, their reduction can be considered a very urgent task. The main route of vibration transmission is through vibration isolation systems for the operator’s seat and cab. The easiest and most cost-effective way to isolate the operator from vibration is through his seat by reducing vibration. The simplest and most reliable vibration protection systems with one degree of freedom limited by vertical movements of the chair can be used for the chairs. Vibration protection mechanisms and systems with quasi-zero rigidity are considered promising. They provide constant static force over a certain range of movement of the object. The task of developing mathematical models describing vibration protection systems with quasi-zero rigidity is urgent. In the Matlab software package using the Simscape library for modeling physical elements, a simulation mathematical model of the vibration protection system of a chair with one degree of freedom has been developed. The base of the chair in the developed model performs harmonic sinusoidal movements. The output parameters of the developed mathematical model are the time dependences of the chair coordinates and accelerations. The blocks used in the model are described, the static force characteristics are given, given using the Hermite spline. The model includes a block of hard movement restrictions. An example of using the developed simulation mathematical model of the chair is given. The developed model makes it possible to specify both the dimensions of the quasi-zero stiffness section and the shape of the curves of the force static characteristics of the vibration protection system. It can be integrated into higher level models.

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Choosing Damping Parameters for the Inertial Orientation System

Herald of the Bauman Moscow State Technical University Series Instrument Engineering ◽

10.18698/0236-3933-2021-3-113-128 ◽

2021 ◽

pp. 113-128

Author(s):

V.P. Podchezertsev ◽

S.V. Topilskaya

Keyword(s):

Natural Frequency ◽

Vibration Suppression ◽

Outer Space ◽

Protection System ◽

Dynamic Vibration ◽

Shock Absorbers ◽

Vibration Protection ◽

Orientation System ◽

Vibration Impact ◽

Vibration Dampers

The article discusses criteria for selecting the vibration protection for the spacecraft inertial orientation system. The considered vibration protection system allows providing acceptable amplitude acceleration for the gyroscopic device sensitive elements under vibration impact on the device body during the spacecraft launching and high angular stability of the position of the sensitive elements relative to the inertial coordinate system during a long period of operation (15 years) in orbit. The proposed vibration protection system consists of shock absorbers (springs) with stable high elastic characteristics under all factors of operation in the outer space and dynamic vibration dampers. The article presents a method for determining the parameters of dynamic vibration dampers taking into account the characteristics of the shock absorber, critical for the damping system of an inertial device. The proposed method for adjusting dynamic vibration dampers consists in suppressing vibrations at the natural frequency f1 of the shock absorption system and providing acceptable values of the gain coefficients of the structure resonant vibration amplitudes near the natural frequency f1. Certain characteristics of the damping system allow realizing the permissible vibration amplification coefficients at resonance, without significantly affecting the level of vibration suppression in the natural frequency zone of the vibration protection object

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NON-LINEAR CORRECTION OF VIBRATION PROTECTION SYSTEM CONTAINING TUNED DYNAMIC ABSORBER

Journal of Sound and Vibration ◽

10.1006/jsvi.2000.3205 ◽

2001 ◽

Vol 239 (2) ◽

pp. 335-356 ◽

Cited By ~ 7

Author(s):

A.M. VEPRIK ◽

V.I. BABITSKY

Keyword(s):

Protection System ◽

Vibration Protection ◽

Non Linear ◽

Linear Correction ◽

Dynamic Absorber

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Choice of configuration and parameters of the vibration protection system for gyroscopic angular velocity meters

Automation. Modern Techologies ◽

10.36652/0869-4931-2021-75-4-187-192 ◽

2021 ◽

Author(s):

Keyword(s):

Angular Velocity ◽

Protection System ◽

Technical Solution ◽

Vibration Damper ◽

Dynamic Vibration ◽

Shock Absorbers ◽

Damping Characteristics ◽

Vibration Protection ◽

High Elasticity ◽

Nonlinear Elastic

The rationale for the choice of a technical solution to the issue of vibration protection of gyroscopic angular velocity meters, built on the basis of dynamically tuned gyroscopes (DTG) is presented. The proposed vibration protection system consists of shock absorbers with high elasticity and dynamic vibration dampers (DVD) with nonlinear elastic and damping characteristics. The main factors that determine the peculiarities of choosing a vibration protection system for precision gyroscopic devices are indicated. Keywords dynamically tuned gyroscope (DTG); dynamic vibration damper (DVD); vibration protection system; gyroscopic angular velocity meter

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Development of a subsystem for automatic protection of submersible pumps based on mathematical modeling

MATEC Web of Conferences ◽

10.1051/matecconf/201822604028 ◽

2018 ◽

Vol 226 ◽

pp. 04028

Author(s):

Alexander V. Pilipenko ◽

Andrei A. Tashev ◽

Nail K. Sharifov

Keyword(s):

Mathematical Modeling ◽

Mathematical Model ◽

Mathematical Modelling ◽

Protection System ◽

Piston Pump ◽

The Mathematical Model

In this paper, the authors produce a mathematical modelling of a piston pump, develop algorithms for the operation of a protection system, taking into account the results of mathematical modelling. The authors test the mathematical model on the operation of real equipment and analyze its accuracy.

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Adapted Bouc-Wen Analytical Model for Romanian SERB-C Seismic Dampers Used in Buildings Protection System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.823.91 ◽

2016 ◽

Vol 823 ◽

pp. 91-94 ◽

Cited By ~ 1

Author(s):

Adriana Ionescu ◽

Cristian Burada ◽

Mihai Negru

Keyword(s):

Mathematical Model ◽

Computational Simulation ◽

Experimental Tests ◽

Protection System ◽

Hysteretic Model ◽

Specific Adaptation ◽

Analytical Simulation ◽

The Mathematical Model ◽

Force Displacement ◽

Unusual Shape

In this paper is presented a new mathematical model which is intended to simulate the hysteretic phenomenon of SERB-C Romanian friction device for damping and dissipation of earthquake energy used for buildings. These devices have unusual shape of force-displacement loop which can be simulated with our new model which represents a specific adaptation of the well known Bouc-Wen hysteretic model. The purpose of this analytical simulation is to determine a relation for the hysteretic loop which was obtained by experimental tests performed by the authors. The mathematical model presented in this paper can be used in computational simulation of a building protected with these types of devices, in order to determine the anti-seismic performances of a Romanian friction building protection system.

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