ВЛИЯНИЕ КОНСТРУКТИВНЫХ ЭЛЕМЕНТОВ И МАТЕРИАЛОВ ОБЪЕМНОЙ УЛЬТРАВЫСОКОЧАСТОТНОЙ МЕТКИ, РАЗРАБОТАННОЙ ПО ПРИНЦИПУ ЗАМКНУТОЙ ПОЛОСКОВОЙ ЛИНИИ ПЕРЕДАЧИ, НА ЕЕ РЕЗОНАНСНУЮ ЧАСТОТУ И ДАЛЬНОСТЬ СЧИТЫВАНИЯ ПРИ КОНТАКТЕ С МЕТАЛЛАМИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 764-768
Author(s):  
И.В. Эпов
Keyword(s):  
Mathematical Model ◽  
Resonance Frequency ◽  
Metal Surfaces ◽  
Structural Elements ◽  
Qualitative Explanation ◽  
Rfid Systems

Данная работа посвящена исследованию RFID-систем. Была разработана математическая модель, связывающая конструктивные элементы объемной 3D-метки с ее резонансной частотой, далее бьши спроектированы на ее основе реальные объемные метки, работающие на частоте 867 МГц. Также было дано качественное объяснение сдвига резонансной частоты метки при ее контакте с металлическими поверхностями. This work is devoted to the study of RFID-systems. It presents a mathematical model linking the structural elements of the 3D volumetric label with its resonance frequency, as well as real volumetric labels operating at a frequency of 867 MHz on its basis. Besides, it gives a qualitative explanation of the shift of the resonance frequency of the label in contact with metal surfaces.

scholarly journals A mathematical model for production routing of mechanical engineering products

2021 ◽  
Vol 25 (3) ◽  
pp. 332-341
Author(s):  
I. V. Fokin ◽  
A. N. Smirnov
Keyword(s):  
Mathematical Model ◽  
Mechanical Engineering ◽  
Complex Geometry ◽  
3D Models ◽  
Point Of View ◽  
Structural Elements ◽  
Production Environment ◽  
Automatic Mode ◽  
The Cost ◽  
Production Routing

The aim was to create a mathematical model describing the development of a production (shop-to-shop) routing of mechanical engineering products based on a 3D model and allowing the cost of the final product to be reduced. The developed mathematical model was simulated based on 3D models designed in the Siemens NX system, which were subsequently imported into the *stp format and recognized by a designed module written in the Phyton programming language. The factors of the production environment affecting the formation of the production routing of mechanical engineering products were determined. A diagram of the algorithm for the “constructive element - technological operation - means of technological equipment (equipment-tool)” relationship was developed. Based on the results of testing the developed mathematical model, the use of neural networks as a tool for the implementation and automation of the work was found advantageous as compared to the standard scheme of work of a process engineer when developing a production routing of mechanical engineering products. These advantages include a decrease in the time for the development of a routing and the cost of the final product. The developed model has a practical limitation consisting in a rather complex geometry of some structural elements of a unit, which impedes the development of an algorithm for recognizing their structure. The use of a neural network prototype in automatic mode is advisable for relatively simple parts (including a flange, hole, chamfer and rounding). However, since the number of simple units from the recognition point of view amounts to about 40% among the nomenclature of manufactured units, the reduction in the development time of the technological process in comparison with the conventional approach comprises only 10–25% of the total time of technological preparation.

scholarly journals Differential equations of the start of motion of elasticly coupled inert bodies on the example of a train with elastic couplings

2021 ◽  
pp. 45-51
Author(s):  
Igor Popov ◽  
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Friction Force ◽  
Static Friction ◽  
The State ◽  
Structural Elements ◽  
Ground Vehicle ◽  
Inert Mass ◽  
The Moment ◽  
Elastic Couplings

The starting mode for a ground vehicle is the most difficult. An effective way to pull off a train is to select coupling clearances. In this case, the cars are set in motion consequently, and the inert mass, as well as the static friction force immediately at the moment of starting, are minimal. This method, however, has two significant drawbacks – a small fixed value of the gaps in the couplings, which limits the effectiveness of the method and the shock nature of the impulse transmission, which negatively affects the state of the structural elements of the train. These disadvantages can be avoided by using elastically deformable couplings. The aim of this work is to construct a mathematical model of "easy" starting of a train with elastic couplings. The softening of the starting mode of the train is essentially due to the replacement of the simultaneous starting of the sections with alternate ones.

Approbation of the Mathematical Model of Adhesive Strength with Viscoelasticity

2019 ◽  
Vol 816 ◽  
pp. 96-101
Author(s):  
Stepan V. Litvinov ◽  
Xuan Zhen Song ◽  
Serdar B. Yazyev ◽  
Artur Avakov
Keyword(s):  
Mathematical Model ◽  
Adhesive Strength ◽  
Adhesive Joint ◽  
Epoxy Resins ◽  
Polymeric Materials ◽  
Critical Value ◽  
Structural Elements ◽  
Long Period ◽  
Tangential Stresses ◽  
The Mathematical Model

Expressed viscoelasticity of polymeric materials which can develop over a long period of time prevents their widespread. Some types of polymers, such as epoxy resins, can be used to connect various structural elements. The destruction in this case can be caused by the growth of tangential stresses in the adhesive joint and their achievement of some critical value τadhezive, at which the adhesive joint is destroyed.

A New Design of Vehicle Seat Intended to Alleviate Lower Back Pain

1989 ◽  
Vol 111 (3) ◽  
pp. 261-262 ◽  
Author(s):  
D. A. Johnson ◽  
J. C. Samin ◽  
M. Neve
Keyword(s):  
Mathematical Model ◽  
Back Pain ◽  
Spinal Column ◽  
Vertical Motion ◽  
Simple Mathematical Model ◽  
Qualitative Explanation ◽  
Lower Back ◽  
Vibrating Table ◽  
Vehicle Seat ◽  
Back Rest

The novelty in the proposed seat design consists in allowing a free vertical motion of the back rest, so as to decrease the strain on the spinal column. Road and vibrating table tests show that the strain is indeed considerably reduced. A simple mathematical model of the seated human body provides a qualitative explanation of this improvement.

The Control of Vibration Transmissibility Using an Electrodynamic Actuator – Passive Solution

2013 ◽  
Vol 436 ◽  
pp. 158-165
Author(s):  
A. Mihaela Mîţiu ◽  
Daniel Constantin Comeagă ◽  
Octavian G. Donţu
Keyword(s):  
Mathematical Model ◽  
Resonance Frequency ◽  
Mechanical System ◽  
Electrical Parameters ◽  
System Operation ◽  
Maximum Variation ◽  
Vibration Transmissibility ◽  
Technical Solutions ◽  
The Mathematical Model

Starting with the mathematical model of a simple electro-mechanical system with 1 DOF, are identified the electrical parameters which may influence the efficiency of control of the system transmissibility using an electrodynamic actuator. Based on simulation of system operation and determination of transmissibility are obtained Bode diagrams and diagrams that shows the maximum variation of the resonance frequency of the system when varying the electrical parameters of the actuator. In the paper is indicated the limits of the theoretical and practical technical solutions to control mechanical transmissibility of a system using an electrodynamic actuator.

scholarly journals Modeling of physical wear assessment of zinc coating of space steel frame road structures for road safety information systems

2021 ◽  
pp. 25-31
Author(s):  
Serhiy Bilyk ◽  
Artem Bilyk ◽  
Eugen Tsyupyn ◽  
Oleksandr Glitin
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Safety Information ◽  
Zinc Coating ◽  
Atmospheric Precipitation ◽  
Corrosive Wear ◽  
Full Scale ◽  
Operating Conditions ◽  
Structural Elements ◽  
Steel Trusses

The article developed an improved physical and mathematical model of the corrosive wear of zinc coating of steel structures in a city. The research is based on full-scale experimental data for determining the wear of a zinc coating of full-scale metal spatial structures of frame road structures for informational safety systems on roads after 10 years of operation in the conditions of Kyiv. The frame structure consists of metal columns and a steel crossbar frame. The crossbar frame is a spatial block of two steel trusses. The block of trusses is assembled from unified spatial sections united by vertical and horizontal ties, and which are connected by flange nodes of a special design. All structural elements are made of rolled tubes. Based on the research results, an approach to assessing the physical wear of the zinc coating of the spatial structural system is proposed. According to the peculiarities of the arrangement of elements in frame structures, and, accordingly, to different conditions and operations, an approach is proposed to assess the corrosive wear of a zinc coating for various groups of elements: columns, spatial block of two steel trusses, flange nodes. The physical and mathematical model is based on the working hypothesis of uneven wear of the zinc coating over time. It was found that for each group of structural elements, the conditions of the gaseous environment, the effects of atmospheric precipitation, wind speed, temperature changes individually affect the reduction of the zinc coating. The obtained experimental data were used to determine the parameter of the rate of decrease in the zinc coating of the physical and mathematical model. The results of the research and the development of the methodology helped to establish the operating conditions of the zinc coating according to the criterion of the rate of wear of the zinc coating, to classify the category of aggressiveness of the environment for each group of structural elements. Also, studies allow predicting the service life by reducing the thickness of the zinc coating, as well as the wear of the zinc coating in time in the subsequent period of operation. The methodology is universal and can be extended to other types of galvanized metal structures.

scholarly journals MATHEMATICAL MODELING OF A NEW METHOD OF THERMAL PROTECTION BASED ON THE INJECTION OF SPECIAL COOLANTS

2019 ◽  
Vol 16 (32) ◽  
pp. 598-607
Author(s):  
Vladimir F. FORMALEV ◽  
Sergey A. KOLESNIK ◽  
Ekaterina L. KUZNETSOVA
Keyword(s):  
Mathematical Model ◽  
Liquid Film ◽  
Dynamic Viscosity ◽  
Thermal Protection ◽  
Strong Dependence ◽  
Structural Elements ◽  
Mathematical Basis ◽  
Temperature Changes ◽  
Heat Flows ◽  
Mass Evaporation

A closed mathematical model of heat and mass transfer under the non-isothermal filtration through the organized pores of coolants with a strong dependence of dynamic viscosity on temperature with further injection into a viscous gas-dynamic flotation with the formation of liquid film and evaporation under the influence of aerodynamic heat flows has been developed. The aim of the paper is to develop the physical and mathematical basis of thermal protection with the automatic supply of coolant having a strong dependence of dynamic viscosity on temperature (by 3–5 orders of magnitude when the temperature changes by 200–2500°C). Such thermal protection system allows for operating without the mass removal that preserves the geometry of the structural elements at the intensive heating, which is very relevant. To achieve this goal, a mathematical model of the automatic coolant supply with filtration through the organized pores, injection into a high-temperature gasdynamic boundary layer with the formation of the protective liquid film and evaporation is formulated. The results with respect to the mass flow rate of the coolant, the mass evaporation rate of the formed liquid film and the temperatures of the structure which in all cases remain below the evaporation temperature of the cooler have been obtained.

scholarly journals Features of mathematical modelling in the analysis of console-type structures

2019 ◽  
Vol 97 ◽  
pp. 03036 ◽  
Author(s):  
Viktor Orlov
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Strain State ◽  
Point Of View ◽  
Classical Approach ◽  
Structural Elements ◽  
Physical Point ◽  
Cantilever Structure ◽  
The Mathematical Model ◽  
Majorant Method

The article deals with the mathematical model of console-type structural elements. The dynamic load is presented as quasi-static one. The differential equation of bending of an object is nonlinear and has movable singular points in which the solution has discontinuity. From a physical point of view, the object will break (collapse) in this place. The application of the majorant method to the solution of the problem allows, in contrast to the classical approach, establishing the boundaries of the solution area and to construct an analytical approximate solution to the problem with a given accuracy. As a result, it’s possible to calculate the displacement at any point of the cantilever structure and estimate the stress-strain state of the object.

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