scholarly journals Vibration parameters and indicators of a dynamic tillage tool

2021 ◽  
Vol 937 (3) ◽  
pp. 032048
Author(s):  
N Dzhabborov ◽  
A Dobrinov ◽  
A Sergeev
Keyword(s):  
Experimental Data ◽  
High Frequency ◽  
Soil Layer ◽  
Travel Speed ◽  
Vibration Velocity ◽  
Dynamic Impact ◽  
Energy Assessment ◽  
Oscillation Energy ◽  
Vibration Parameters ◽  
Elastic Elements

Abstract According to domestic and foreign research on the efficiency of active and passive vibrating tillage tools, the created vibration allows reducing the traction resistance of tillage implements compared to conventional tools, while improving the tillage quality. The study aimed to determine several vibration parameters and indicators of a dynamic tillage tool supplied with an energy storing and transmitting device: frequency and amplitude of oscillations, absolute velocity, vibration velocity, acceleration of vibration, a force of inertia, and oscillation energy. The study applied the energy assessment methods of tillage tools with the measuring and information system designed at IEEP – branch of FSAC VIM; analysis and generalisation of experimental data. Vibration variables were determined by the strain-gauge method. The study revealed a significant effect of oscillation frequency and amplitude of the tillage tool, depending on the machine travel speed and characteristics of elastic elements, on its vibration velocity and acceleration, the force of inertia and the energy of oscillations.The total increase in these forces owing to a high-frequency dynamic impact may affect the soil layer considerably as an additional loosening. The accumulated impact energy can provide a decrease in the traction resistance of the tillage tool.

scholarly journals The inverse problem of stabilization of a spherical pendulum in a given position under oblique vibration

2021 ◽  
Vol 8 (2) ◽  
pp. 255-269
Author(s):  
Аlexander G. Petrov ◽  
Keyword(s):  
Inverse Problem ◽  
High Frequency ◽  
Initial Conditions ◽  
Vibration Velocity ◽  
Spherical Pendulum ◽  
Acceleration Vector ◽  
Long Time ◽  
Minimum Amplitude ◽  
Vibration Parameters ◽  
Gravity Acceleration

The inverse problem is posed of stabilizing a spherical pendulum (a mass point at the end of a weightless solid rod of length l ) in a given position using high-frequency vibration of the suspension point. The position of the pendulum is determined by the angle between the pendulum rod and the gravity acceleration vector. For any given position of the pendulum, a series of oblique vibration parameters (amplitude of the vibration velocity and the angle between the vibration velocity vector and the vertical) were found that stabilize the pendulum in this position. From the obtained series of solutions, the parameters of optimal vibration (vibration with a minimum amplitude of velocity) are selected depending on the position of the pendulum. The region of initial conditions is studied, of which the optimal vibration leads the pendulum to a predetermined stable position after a sufficiently long time. This area, following N. F.Morozov et al., called the area of attraction.

scholarly journals ESTIMATION OF DYNAMIC EFFECTS FROM VIBRATION DIPPING OF SHEET PILES ON ENVIRONMENTAL BUILDINGS IN CONDITIONS OF WEAK WATER-SATURATED SOILS

2020 ◽  
Vol 11 (3) ◽  
pp. 102-116
Author(s):  
R. A Mangushev ◽  
A. V Gurskiy ◽  
V. M Polunin
Keyword(s):  
High Frequency ◽  
Soil Mass ◽  
Vibration Velocity ◽  
Sheet Pile ◽  
Significant Excess ◽  
Vibration Acceleration ◽  
Dynamic Impact ◽  
High Frequency Vibration ◽  
Soil Foundation ◽  
Water Saturated

In weak, structurally unstable soils, the use of the technology of high-frequency vibration immersion of sheet piles, in some cases, is obviously dangerous, and the issue of assessing the limits of applicability of this technology in certain conditions is relevant. The assessment of the dynamic impact on the soil foundation can be made by the level of vibrations. Regulatory documents impose requirements on the level of vibrations of the surrounding soil mass and buildings, however, it is not entirely correct to assess the influence of the technology of high-frequency vibration driving of sheet piles only by the values of vibration acceleration and vibration velocity. The object of the study is the values of deformations of foundations reinforced with piles. At the experimental construction site, we were carried out for the level of vibrations of foundations reinforced with piles 18 m length, from high-frequency vibration immersion of a pipe sheet pile with a diameter of 1200 mm and a length of 18 m. In the process of driving the sheet piles, we were making constant geodesic control over the deformations of adjoining buildings was carried out. The main results are: the example given in the article shows that when the foundations are strengthened, the deformations of the foundation (settlement) remain within the permissible values, despite the significant excess of the permissible level of vibrations of the building foundations. The proposed methodology for the numerical prediction of base deformations from vibration immersion of sheet piles gives satisfactory convergence with the results of field observations and makes it possible to assess qualitatively and quantitatively the settlements of buildings in the surrounding development from vibration immersion / extraction of sheet piles at the preliminary stages of construction.

scholarly journals High Frequency Magnetoimpedance of FeNi/Cu/FeNi Sensitive Elements with Different Geometries

2009 ◽  
Vol 152-153 ◽  
pp. 373-376 ◽  
Author(s):  
Stanislav O. Volchkov ◽  
Andrey V. Svalov ◽  
G.V. Kurlyandskaya
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
External Magnetic Field ◽  
Finite Elements ◽  
Magnetic Anisotropy ◽  
Constant Magnetic Field ◽  
High Frequency ◽  
Complex Impedance ◽  
Rf Sputtering ◽  
Frequency Range

In this work magnetoimpedance (MI) behaviour was studied experimentally for Fe19Ni81(175 nm)/Cu(350 nm)/Fe19Ni81(175 nm) sensitive elements deposited by rf-sputtering. A constant magnetic field was applied in plane of the sandwiches during deposition perpendicular to the Cu-lead in order to induce a magnetic anisotropy. Sandwiches with different width (w) of FeNi parts were obtained. The complex impedance was measured as a function of the external magnetic field for a frequency range of 1 MHz to 700 MHz for MI elements with different geometries. Some of MI experimental data are comparatively analysed with finite elements numerical calculations data. The obtained results can be useful for optimization of the design of miniaturized MI detectors.

scholarly journals Polynomial approximation of dynamic signals of single platform railway scales

2021 ◽  
pp. 44-52
Author(s):  
Illia Kolysnychenko ◽  
Victor Tkachov
Keyword(s):  
Experimental Data ◽  
Polynomial Approximation ◽  
Intelligent Systems ◽  
Moving Objects ◽  
Linear Equations ◽  
Real Data ◽  
Travel Speed ◽  
Rolling Stock ◽  
Identification System ◽  
Approximation Process

Purpose. Obtaining an approximating function (or a system of approximating equations), which, with a minimum error, will make approximations to the available data on a train of railway objects through 1 platform scales. Methodology. To solve this problem, numerical methods are used, namely, the approximation by polynomial functions of the nth order. The experimental data on the basis of which the experiments were carried out were obtained from the weighing and identification system of wagon in motion on a single platform scale. The approximation process is automated using a program written in the Python programming language in which the polyPit and polyid functions of the numPy library are used to obtain the polynomial coefficients. Findings. Due to the use of polynomial approximation in data processing from tensometric railroad weighing systems, it was possible to obtain a system of linear equations that, with minimal error, restored the experimental data that were obtained from the existing system of the Severny GOK: Metinvest enterprise. When normalizing the readings of the sensors from conventional units, obtained from the summing box to the range of values [0; 1] it became possible, in percentage terms, to describe a railway object. This makes it possible to avoid the dependence of the final results on the travel speed of the carriage or locomotive, which leads to an increase in the accuracy of the identification of cars in the rolling stock due to the use of the percentage of the axles staying on the weighing platform (approach / exit). It became possible to determine the type of carriage with the same number of axles, but different characteristics of the center space and the base of the rolling stock. Originality.  The novelty is to obtain a general method of approximation of experimental data of the passage of wagons through a single-platform scales, which can be used to train intelligent systems and generate close to real data of the passage of a car (due to the imposition of noise, etc.). Practical value.  Improving the accuracy and speed of the carriage identification as a whole, which reduces the plant downtime, contributes to an increase in the number of weighed and identified moving objects, as well as the ability to identify the type of carriage with the same number of axles in the train. The methods presented in the work can be used both for identification and for tasks, the end result of which is the classification of input data (neural networks, etc.).

scholarly journals Features of the Surface and Subsurface Waves Application for Ultrasonic Evaluation of Physicomechanical Properties of Solids. Part 2. Strenghtned Inhomogeneous Surface Layer

2019 ◽  
Vol 10 (1) ◽  
pp. 69-79
Author(s):  
A. R. Baev ◽  
A. L Mayorov ◽  
N. V. Levkovich ◽  
M. V. Asadchaya
Keyword(s):  
Experimental Data ◽  
Surface Layer ◽  
Spatial Distribution ◽  
Surface Wave ◽  
High Frequency ◽  
Hardened Layer ◽  
Gray Iron ◽  
Physicomechanical Properties ◽  
Inhomogeneous Surface ◽  
Ultrasonic Evaluation

The propagation of a pulsed signal of a surface wave over an object with a non-uniform surface layer, obtained, for example, as a result of surface hardening, with structural damage, is accompanied by the dispersion of the velocity of the wave carrying important information about the parameters of such a layer. The aim of the work is to study the relationship between the acoustic parameters of a pulsed acoustic signal of a surface and subsurface waves and the surface layer of steel specimens hardened by high-frequency hardening, and gray iron-chill. Features of the surface and subsurface waves application for ultrasonic evaluation of physicomechanical properties of solids. Strenghtned inhomogeneous surface layer.A brief analysis of the known works on determining the depth of hardened surface layers by various methods, including high-frequency hardening, cementation, etc., is carried out. Based on the Oulder integral expression. The dependence connecting the wave velocity, its frequency, the depth of the hardened layer and the spatial distribution of hardness represented as a step with a changing slope of its side surface simulating the transition zone of the hardened layer are calculated.Using the pulse method and low-aperture transducers with a frequency of 1−3.8 MHz, the dependences of the surface wave velocity on the cutting height of a layer hardened by HDTV hardening are obtained. A comparison of experimental data and calculations of the theoretical model showed a good qualitative correspondence between them, demonstrate a high «sensitivity» of the method in relation to the nature of the change in hardness over the depth of the hardened layer. It is shown that the proposed approach is promising for solving the inverse problem of restoring the spatial distribution of hardness based on experimental data.The goniometric method was approbated to determine the dependence between amplitude-angle characteristics and depth of the surface steel layers hardened by high-frequency hardening and depth of hardened gray iron specimens layer – with chill. It is shown that the optimal angle corresponding maximum of excited surface wave amplitude in steel specimens is decreasing up to 24–26'vs. hardened depth layer. But when the tested specimens from cast iron this angle decreasing is nearly of 6°. Recommendations on the use of research results in practice are given.

A method to quantify hand-transmitted vibration exposure based on the biodynamic stress concept

2007 ◽  
Vol 221 (8) ◽  
pp. 847-861 ◽  
Author(s):  
R G Dong ◽  
D E Welcome ◽  
J Z Wu
Keyword(s):  
Experimental Data ◽  
High Frequency ◽  
Practical Method ◽  
The Other ◽  
Equivalent Model ◽  
Frequency Effect ◽  
Vibration Exposure ◽  
Stress Cycle ◽  
Vibration Induced White Finger ◽  
Frequency Weightings

This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is the biodynamic stress distributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm.

Impact action of a projectiles on special protective structures and ways to increase their protective capacity

2021 ◽  
pp. 95-100
Author(s):  
A. Andrukhiv ◽  
A. Baranov ◽  
N. Huzyk ◽  
B. Sokil ◽  
M. Sokil
Keyword(s):  
Soil Layer ◽  
Strength Characteristics ◽  
Protective Structure ◽  
Impact Action ◽  
Dirac Delta ◽  
Wood Flooring ◽  
Protective Element ◽  
Applied Forces ◽  
Protective Structures ◽  
Elastic Elements

A method for studying the reaction of elastic elements of protective structures to a series of impact actions of shells has been developed. In the work, the elastic elements of the protective structure are modeled by homogeneous beams, and the dynamic action of the shells is simulated by instantaneous point-applied forces. A mathematical model of this dynamic process is constructed, which is a boundary value problem for a hyperbolic equation with an irregular right-hand side. The latter is described using Dirac delta functions. Cases of both fixed and free ends of protective elements are considered. The main ideas of perturbation methods are used for the researches carried out in the work. Analytical dependences for the description of elastic deformations of a protective element which are basic for definition of its strength characteristics are received. They and the graphical dependences built on their basis for specific cases show that the dynamic deformations of the protective element for the fixed ends are greater in the case of the projectile closer to its middle, at the same time for the free ends – closer to the end. With regard to the modernization of protective structures, the dynamic effect on their elements can be reduced by using elastic reinforcement or changing the method of fixing the ends of the protective element: elastic or with a certain angle of inclination of the bearing surfaces. It is proposed to use special plastics, soil layer, flexible wood flooring, etc. as elastic reinforcement. The technique used in the work is the basis for determining the strength characteristics of protective elements, and from so – to check the reliability of the protective structure; study of the dynamics of protective and similar types of structures, taking into account the nonlinear characteristics of the elastic elements of protective structures; study of more complex oscillations of elements of protective structures. In the case of a series of impacts, it is obvious that the amplitude of deflection of the protective element after each impact will increase over time, because the model does not take into account the force of viscoelastic friction. These tasks will be the subject of further research.

High-frequency pulse train generation in dispersion-decreasing fibre: using experimental data for the metrology of longitudinally nonuniform fibre

2021 ◽  
Vol 51 (5) ◽  
pp. 427-432
Author(s):  
I S Panyaev ◽  
D A Stoliarov ◽  
A A Sysoliatin ◽  
I O Zolotovskii ◽  
D A Korobko
Keyword(s):  
Experimental Data ◽  
High Frequency ◽  
Pulse Train ◽  
Pulse Train Generation ◽  
Frequency Pulse
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