Mathematical Model of Wood Drilling Taking into Account the Mutual Infl uence of Electric Motors of Feed and Cutting

2021 ◽  
Vol 2 (43) ◽  
pp. 48-53
Author(s):  
Viktor P. Lapshin ◽  
◽  
Il’ya A. Turkin ◽  
Valentin Yu. Omelechko

The Russian economy currently needs new approaches to solving old problems, that is, such methods that would increase the efficiency of production. In the case of woodworking, we can talk about the introduction of new management principles that ensure a higher quality of processing, even on old woodworking machines and centers. The implementation of such methods is impossible without the development of modern mathematical models of the cutting process, including wood drilling. (Research purpose) The research purpose is in constructing of a mathematical model that reflects the dynamics of wood processing by drilling, which is interconnected through the cutting process. (Materials and methods) Authors used mathematical and numerical modeling with extensive use of mathematical software packages, such as the MatLab mathematical modeling environment. (Results and discussion) The article presents the graphs of the drilling process state in the form of numerical simulation results carried out in the Matlab environment. (Conclusions) The article presents the developed model of the dynamics of the cutting system in two versions. The first version takes into account only the moments and forces associated with the formation of the cutting force in the processing zone. The second model includes an additional moment of resistance associated with the accumulation of chips in the chip-removing channels of the drill. This process has a significant impact on the stability of drilling, with the accumulation of chips in excess of a certain value, the system loses stability and there are raise the possibility of failure of both the drill and the entire spindle assembly. The developed mathematical model of the drilling control system, represented by the system of equations, adequately describes the process of wood processing by drilling on woodworking equipment.

2018 ◽  
Vol 13 (2) ◽  
pp. 76-76
Author(s):  
Валерий Белов ◽  
Valeriy Belov ◽  
Леонид Рыбаков ◽  
Leonid Rybakov ◽  
Светлана Овчукова ◽  
...  

A brief analysis of suspension mechanisms and ways to improve the quality of press harvesting for flax harvesting is considered. By researching the mathematical model, the authors prove the possibility of increasing the stability of the elastic characteristics of the suspension mechanisms by changing the angle between the levers or changing the geometry of the structure, for example, the attachment point of a two-arm lever. Particular attention is drawn to the new term “reduced rigidity” of the suspension mechanism. Using this notion and the method of its determination, the authors recommend determining the optimal value of the reduced stiffness of the suspension in the way of mathematical modeling and using this indicator as the main optimization parameter. The results of theoretical and experimental studies were presented by the authors in the form of elastic characteristics of the suspension mechanisms. When conducting a study of the mathematical model, it is suggested to take into account the condition of equality of the maximum values of the moments of forces from the action of the tension forces of the belts or the mass of the working element and the moment of forces acting on the side of the tension springs. During the research of the suspension mechanism, the actual dimensions of the PR-1.5 baler design were adopted. At the same time, we briefly describe the design of the improved tensioning mechanism of a baler for flax harvesting. A rather detailed analysis is given by the authors of the obtained elastic characteristics of the suspension mechanism. Some new features of the elastic characteristics of the suspension mechanism that have not been previously detected are described. To confirm the correctness of the reasoning, the authors implemented their research in a real press-picker and conducted field research that confirmed the possibility of improving the quality of the upgraded version of the machine. To confirm the results of the research, the authors presented a fragment of the field test protocol. The task is solved, uniformity of the roll density is ensured and its density is increased.


Author(s):  
Л.Д. Бухтояров ◽  
И.В. Григорьев ◽  
О.А. Куницкая ◽  
А.Е. Лукин ◽  
Д.Е. Куницкая

Из древесины производится около 20 тысяч наименований продукции, причем около 95% приходится на продукцию химической и механо-химической переработки древесины. Большая часть таких производств в качестве сырья потребляет технологическую щепу, к которой предъявляются требования по наличию в ней коры, гнилей и минеральных включений. Наиболее трудо- и энергоемкой операцией технологического процесса по производству технологической щепы является окорка балансовой древесины, которая в подавляющем большинстве случаев производится методом групповой окорки в окорочных барабанах различной конструкции. В статье представлена математическая модель процесса групповой окорки лесоматериалов в окорочных барабанах, позволяющая оценивать один из основных параметров групповой окорки лесоматериалов – время их обработки, при котором будут минимизированы потери древесины без снижения качества окорки, с учетом конструктивных элементов барабана, параметров балансов, их свойств и температуры. Учтен вероятностный характер таких показателей, как время окорки, физико-механические свойства коры и древесины, особенности распределения слоев коры по глубине, что обусловило необходимость применения математической модели, основанной на принципах ситуационного моделирования процессов перехода лесоматериала из одного состояния в другое. Методика расчета и управления основными параметрами процесса позволяет разрабатывать организационные, технологические и технические мероприятия, обеспечивающие стабильность качественных показателей групповой окорки лесоматериалов в окорочных барабанах. Также модель представлена в виде функциональной блок-схемы, основанной на графическом интерфейсе Matlab с приложением Simulink. Используя наборы блоков Simulink, отвечающих за константы, переменные, функции, и вычислительные операции, организован процесс расчета основных параметров объектно-ориентированным ме­тодом. Wood is produced about 20 thousand kinds of products, with about 95% products of the chemical and mechano-chemical processing of wood. Most of these industries as raw material consumes wood chips, which are requirements for the presence of bark, rot and mineral inclusions. Most labor and energy intensive operation of the technological process for the manufacturing of wood chips is the debarking of pulpwood, which in the vast majority of cases, produced by a group of debarking in debarking drums of various designs. The article presents a mathematical model of the process of group debarking wood in debarking drums allows one to assess one of the key parameter group of debarking wood – processing times, which will be minimized wood losses without reducing the quality of the debarking, taking into account the structural elements of the drum, the balance parameters, their properties and temperature. Account the probabilistic nature of such indicators as: debarking, physical and mechanical properties of bark and wood, the distribution of layers of crust at depth, which necessitated the use of mathematical models based on the principles of situational simulation of the transition branch from one state to another. Calculation method and basic parameters of the process allows us to develop organizational, technological and technical measures ensuring the stability of quality indicators of group debarking wood in debarking drums. Also, the model presented in the form of functional block diagrams based on the graphical user interface of Matlab with Simulink application. Using the Simulink block sets of charge constants, variables, functions, and compute the organized process of calculating the basic parameters of the object-oriented method.


Transport ◽  
2009 ◽  
Vol 24 (2) ◽  
pp. 170-179 ◽  
Author(s):  
Vidmantas Vansauskas ◽  
Marijonas Bogdevičius

The article reviews the stability of an automobile on the road pavement with ruts. The problems of road safety depend on many factors. One of those is the quality of the road surface. Big heavy lorries deform the road surface causing ruts especially in the first line of the road. The article analyzes the influence of the geometry of ruts on the stability of the automobile. A mathematical model of a 3D automobile and the interaction between wheels and the road surface and the geometry of the road surface are presented. The mathematical criterion of the stability of the moving automobile on the road surface with ruts is laid down. The results of mathematical simulation and the criterion of the stability of the moving automobile (60 km/h) on the road surface depending on the depth of ruts are introduced.


2021 ◽  
Author(s):  
Mohammad Baraheni ◽  
Mohammad Reza Shabgard ◽  
Saeid Amini

Abstract Complex geometries can be produced by using additively manufacturing method (AM). As usual, the AM parts have rough surfaces in which post processing operations are needed. One of the useful operations is ultrasonic drilling process. In this process, an additional movement is added to the cutting tool to improve the machinability factors. In this study, poly lactic acid(+) was selected as workpiece where the quality of the holes generated by ultrasonic drilling, were investigated. The examination parameters were delamination, circularity, and cylindricality. As a result, it was shown that UD process could properly improve the examination parameters. It was explained that harmonic movement of drill bit in UD improved the stability of the process by a decrease in cutting forces and chip adhesion. Moreover, a significant reduction was observed in delamination factor by using ultrasonic vibrations.


2019 ◽  
pp. 3-8
Author(s):  
N.Yu. Bobrovskaya ◽  
M.F. Danilov

The criteria of the coordinate measurements quality at pilot-experimental production based on contemporary methods of quality management system and traditional methods of the measurements quality in Metrology are considered. As an additional criterion for quality of measurements, their duration is proposed. Analyzing the problem of assessing the quality of measurements, the authors pay particular attention to the role of technological heredity in the analysis of the sources of uncertainty of coordinate measurements, including not only the process of manufacturing the part, but all stages of the development of design and technological documentation. Along with such criteria as the degree of confidence in the results of measurements; the accuracy, convergence, reproducibility and speed of the results must take into account the correctness of technical specification, and such characteristics of the shape of the geometric elements to be controlled, such as flatness, roundness, cylindrical. It is noted that one of the main methods to reduce the uncertainty of coordinate measurements is to reduce the uncertainty in the initial data and measurement conditions, as well as to increase the stability of the tasks due to the reasonable choice of the basic geometric elements (measuring bases) of the part. A prerequisite for obtaining reliable quality indicators is a quantitative assessment of the conditions and organization of the measurement process. To plan and normalize the time of measurements, the authors propose to use analytical formulas, on the basis of which it is possible to perform quantitative analysis and optimization of quality indicators, including the speed of measurements.


2010 ◽  
pp. 108-117 ◽  
Author(s):  
I. Smotritskaya ◽  
S. Chernykh

The article analyzes the conceptual framework of public procurement system as an integral part of public regulation to ensure effective management of public resources. The authors consider the problems of transition to a new "quality" of the procurement system, increasing its innovative activity. They put forward proposals for institutional framework and mechanisms of regulating procurement, meeting the needs in innovative upgrading and modernization of the Russian economy.


Author(s):  
Denys Popelysh ◽  
Yurii Seluk ◽  
Sergyi Tomchuk

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.


2020 ◽  
Vol 8 (8) ◽  
pp. 1476-1496
Author(s):  
V.V. Smirnov

Subject. The article discusses Russia’s economy and analyzes its effectiveness. Objectives. The study attempts to determine to what extent Russia’s economy is effective. Methods. The study is based on the systems approach and the statistical analysis. Results. I discovered significant fluctuations of the structural balance due to changing growth rates of the total gross national debt denominated in the national currency, and the stability of growth rates of governmental revenue. Changes in the RUB exchange rate and an additional growth in GDP are the main stabilizers of the structural balance, as they depend on hydrocarbon export. As a result of the analysis of cash flows, I found that the exports slowed down. Financial resources are strongly centralized, since Moscow and the Moscow Oblast are incrementing their share in the export of mineral resources, oil and refining products and import of electrical machines and equipment. Conclusions and Relevance. The fact that the Russian economy has been effectively organized is proved with the centralization of the economic power and the limits through the cross-regional corporation, such as Moscow and the Moscow Oblast, which is resilient to any regional difficulties ensuring the economic growth and sustainable development. The findings would be valuable for the political and economic community to outline and substantiate actions to keep rates of the economic growth and sustainable development of the Russian economy.


Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.


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