Наукові видання

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https://repository.sspu.edu.ua/handle/123456789/395

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Перегляд Наукові видання за Автор "Dieniezhnikov Serhii Serhiiovych"

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  • Документ
    Constructing a Model of the Axis Form in a S-Shaped Riser of a Cultivator Paw
    (Eastern-European Journal of Enterprise Technologies, 2024) Pylypaka S.; Hropost V.; Volina T.; Kalenyk Mykhailo Viktorovych; Ruzhilo Z.; Dieniezhnikov Serhii Serhiiovych; Tarelnyk N.; Tatsenko O.; Semirnenko S.; Motsak Svitlana Ivanivna; Пилипака С.; Хропост В.; Воліна Т.; Каленик Михайло Вікторович; Ружило З.; Дєнєжніков Сергій Сергійович; Тарельник Н.; Таценко О.; Семірненко С.; Моцак Світлана Іванівна
    When cultivating the soil, a force of resistance to the movement of cultivator paw acts on it. It has a variable value and causes a moment of force applied to the riser of the paw. Under the action of the moment, the elastic axis of the riser changes its shape. This affects the position of the paw in the soil. The form of an S-shaped riser whose elastic axis consists of two circle arcs has been considered in this study. During cultivator operation, one part of the riser bends, increasing the curvature of the elastic axis, and the other, on the contrary, unbends, that is, its curvature decreases. The modeling of the shape of the elastic axis of the paw riser is based on the theory of resistance of materials, according to which the curvature of the elastic axis of the cantilevered band is directly proportional to the applied moment and inversely proportional to its stiffness. If the shape of the cross-section of the riser along its entire length is unchanged and the properties of the metal are also the same, then the stiffness is constant. In the case of small deflections of the band, the linear theory of bending is used, but the deflections in the riser are significant, so the nonlinear theory has been used for this case. At the same time, it is taken into account that the elastic axis of the riser already has an initial curvature, the sign of which changes after passing through the point of connection of the component arcs. To model the shape of the elastic axis of the S-shaped paw riser, the deformation of the arcs of the circles that form this paw was calculated separately. Numerical integration methods were used to find the shape of the deformed elastic axes of both parts of the riser. They were connected into a whole and a deformed elastic axis of the S-shaped riser was obtained. Two variants of the riser with different lengths of their elastic axis, but the same height and the same angle of entry into the soil, were considered. The combination of the component arcs of the riser shows that, under the action of the same force, the deviation from the specified movement depth for one riser is 2 cm, and for the other – 4 cm
  • Документ
    Construction of Mathematical Model of Particle Movement by an Inclined Screw Rotating in a Fixed Casing
    (Eastern-European Journal of Enterprise Technologies, 2023) Volina T.; Pylypaka S.; Kalenyk Mykhailo Viktorovych; Dieniezhnikov Serhii Serhiiovych; Nesvidomin V.; Hryshchenko I.; Lytvynenko Ya.; Borodai A.; Borodai D.; Borodai Ya.; Воліна Т.; Пилипака С.; Каленик Михайло Вікторович; Дєнєжніков Сергій Сергійович; Несвідомін В.; Грищенко І.; Литвиненко Я.; Бородай А.; Бородай Д.; Бородай Я.
    Screw conveyors are used to move bulk materials vertically upwards, horizontally, and at an angle to the horizon. The processes that take place when particles are moved by a screw conveyor in vertical and horizontal directions have been studied. There is a significant difference between them: for transportation in the vertical direction, the necessary conditions must be ensured (sufficient angular speed of rotation of the screw), and for horizontal transportation, the movement of the particle occurs at any angular speed of rotation of the screw. Therefore, when changing the inclination of the axis of the screw, there comes a moment when transportation becomes possible, while it was impossible in the vertical direction. This paper considers the movement of a particle under the condition that it simultaneously contacts two surfaces: the moving surface of the screw and the stationary surface of the cylindrical casing in which the screw rotates. Their common line along which the particle slides is a helical line – the periphery of the screw. The particle slides along the helical line of the rotating screw, i.e., it is in relative motion with respect to it. At the same time, it slides along the surface of the casing, relative to which it is in absolute motion. The trajectory of the particle’s absolute motion is its sliding track on the casing surface. When constructing differential equations of the relative motion of particles, the forces applied to the particle were taken into account. The initial position was taken to be the vertical direction of the screw to transport the particle upwards. If an auger in a cylindrical casing is tilted from the vertical direction to a certain angle, then all applied forces (except the force of weight) will also tilt to this angle. On the basis of this, generalized differential equations of the relative motion of a particle during its transportation by an inclined screw were built. They made it possible to derive a generalized mathematical model of the movement of a particle by an inclined screw that rotates inside a fixed casing.
  • Документ
    Designing a Helical Knife for a Shredding Drum Using a Sweep Surface
    (Eastern-European Journal of Enterprise Technologies, 2024) Pylypaka S.; Hropost V.; Nesvidomin V.; Volina T.; Kalenyk M.; Volokha M.; Zalevska O.; Shuliak I.; Dieniezhnikov Serhii Serhiiovych; Motsak Svitlana Ivanivna; Пилипака С.; Хропост В.; Несвідомін В.; Воліна Т.; Каленик Михайло Вікторович; Волоха М.; Залевська О.; Шуляк І.; Дєнєжніков Сергій Сергійович; Моцак Світлана Іванівна
    The object of this paper is a helical blade in a shredding drum from a sweep surface. Such drums are used in harvesters for crushing plant mass. If the flat blades are installed on the drum, cutting of the plant mass occurs simultaneously along the entire length of the blade. This could cause a pulsating dynamic load. If a flat knife with a straight blade is installed at an angle to the axis of the drum, then the distances from it to the points of the blade will be different, as well as the cutting conditions along the blade. The elliptical shape enables the same distance from the axis of rotation to the points of the blade, but this does not solve the problem. Many short flat knives with a straight blade can be mounted on the drum, placing them in such a way that the time between the individual knives is minimized. However, all these disadvantages can be eliminated by a helical knife with a blade in the form of a helical line. The design of a helical knife from an unfolding helicoid has been considered. In differential geometry, the bending of unfolded surfaces of zero thickness is considered. Bending of the workpiece into a finished product occurs with minimal plastic deformations, the magnitude of which depends on the thickness of the workpiece sheet. The methods of differential geometry of unfolding surfaces were applied to the analytical description of the surface of the helical knife. The parametric equations of the unfolding helicoid were derived according to the given structural parameters of the knife in space and on the plane. That has made it possible to mathematically describe the contour lines that cut the knife from the surface and on its sweep. Formulae for calculating a flat workpiece through the structural parameters of the knife have been derived. Thus, with the specified structural parameters of the knife R=0.25 m, τ=20°, j=65°, according to the resulting formula, we find the radius of the knife blade on a flat workpiece: R0=4.8 m
  • Документ
    Determining the Shape of a Flexible Thread in the Field of Horizontal and Vertical Forces
    (Eastern-European Journal of Enterprise Technologies, 2024) Volina T.; Pylypaka S.; Nesvidomin V.; Kalenyk Mykhailo Viktorovych; Spirintsev D.; Dieniezhnikov Serhii Serhiiovych; Hryshchenko I.; Rebrii A.; Herashchenko T.; Soloshchenko Viktoriia Mykolaivna; Воліна Т.; Пилипака С.; Несвідомін В.; Каленик Михайло Вікторович; Спірінцев Д.; Дєнєжніков Сергій Сергійович; Грищенко І.; Ребрій А.; Геращенко Т.; Солощенко Вікторія Миколаївна
    In theoretical mechanics, the equilibrium of a flexible, inextensible thread is considered, to which the tension force of its ends and the distributed force of weight along the length of its arc are applied. An unsolved problem is finding the shape of the thread under the action of other distributed forces. This study has considered the equilibrium of a completely flexible thread, to which, in addition to this force, a transverse distributed force is applied. A sail serves as an example. Wind of equal intensity in the plane of the orthogonal section of the sail can be considered a distributed force. The sail can be cut into narrow strips with the same shape of the curves of the cross-section, which are equal to the cross-section of the sail as a whole. The theory of flexible thread is applied in the current study. The task is reduced to finding the curve of the cross-section of the sail. The object of research is the formation of a cylindrical surface from a flexible thread under the action of distributed forces applied to it. An important characteristic of the shape of a flexible thread is its curvature. Its dependence on the length of the arc was found and it was established that the found curve is a chain line (catenary). This is the feature of the current research and its distinguishing characteristics. The significance of the results stems from the derived analytical dependences, according to which the change in the ratio between the distributed forces acting on the flexible thread deforms it, but it retains the shape of the catenary. At the same time, the angle of deviation of its axis of symmetry from the vertical changes. In the absence of a horizontal distributed force and the presence of only a distributed force of weight, the axis of symmetry of the chain line is directed vertically – at an angle of 90° to the horizontal. If they are equal, this angle is 45°. Scope of application includes structures with stretched supporting wires, conveyor belts, flexible suspended ceilings, the shape of which can be calculated by using our results.