Discrete-continuous simulation and analysis of forced oscillations of (heavy) rope of crane loading mechanism in its process

The analysis of forced oscillations and waveformations of heavy ropes of hoisting mechanisms of cranes in the processes of starting the latter is carried out. The main parameters of the resulting waveforms in the ropes for different ways of lifting the load ("with a pickup", "by weight") are determined. The influence of gravity on the rope and the longitudinal oscillations arising in it, as well as on the longitudinal waveforms arising inside it are investigated. The rope of the lifting mechanism, in this case, is considered as a tensile rod. The laws of motion of cross-sections of ropes are established, according to which the forces arising in ropes are minimized during the startup of hoisting mechanisms of cranes. The application of the integrodifferential equation, which adequately describes the oscillations of the rope system of cargo cranes, and also takes into account the frequencyindependent internal friction in these systems, which accompanies the oscillatory processes in the ropes during transient reagents for their differentiation by different ways of lifting loads. The parameters of the established harmonic oscillations of the rope system of cranes for long-term lifting of the load and taking into account the inertial properties of the rope (considerable length), as well as the magnitude of the static movement of the rope (for different ways of lifting loads) are determined.

Model of stochastic process of restoration of working capacity of agricultural machine in inertial systems with delay

In the article the analysis of existing agricultural machines in a healthy state, followed by work on the maintenance system subject to the conditions of reforming of the agrarian sector. Under maintenance refers to the complex of works on maintenance of working capacity or serviceability of the products during use by adjusting, knowledgeable, filling and retaining work. For the assessment of the alternatives it is advisable to conduct morphological analysis of the entire set of possible solutions to the research problem presented in a morphological matrix, which presents the basic functions of the machine and options the subject of the forms of their implementation. Theoretical research has provided the answer to two fundamental questions – how to change maintenance system depending on the level of development of agricultural production, and what parameters must have the system maintenance service to perform the appropriate intervention with the minimum technologically necessary costs of resources and investment. Assessment of the level of maintenance of agricultural machinery is provided to carry on the totality of organizational and technical factors, formalized through parts and complex indicators, in two phases. The first evaluation of using of the indicators for each factor separately. Second – assessment of a complex indicator (for all factors).

Numerical simulation as method of research and improvement of side ventilation system in poultry house with traditional ranking of exhaust fans

In order to ensure a normalized and uniform internal environment in the poultry house, for large productions, new ventilation systems are needed. As part of this study, numerical simulations of the lateral ventilation system in the poultry house during the winter period of the year were performed. The result is the fields of velocities, current lines and pressures in the poultry house in a 3D setting. It was found that the supply valves located at a height of 200 mm from the floor work much more efficiently than in the traditional setting at a height of 400 mm. Installation of walls on the inside of the poultry house frame, as well as reducing the height of the floor improve the aerodynamics in the poultry house.

Justification of risk-based approach of operation of mobile agricultural equipment on example of details of separate units of tractors

It is shown that in order to justify the extension of the service life of the machine beyond the resource set by the developers, it is necessary to focus on the allowable risks of accidents that can lead to accidents. After all, today for mobile agricultural machinery, the operation of which is associated with high-risk work, the concept of acceptable (acceptable) risk is not used, which does not allow to assess the danger of being on fields, farms and roads without machinery, with exhaustion of installed resources. The purpose of researches is to justify the permissible risk of exploitation of mobile agricultural machinery, in array of details and elements of constructions which have accumulated defects (damage). This paper analyzes the kinetics of accumulation of operational defects in the array of parts of individual components (systems) of tractors. MTZ-80 tractors (82) were chosen as the object of research, as one of the most common in Ukraine. To detect cracks, a developed eddy current flaw detector was used, the sensitivity of which allowed to find cracks several millimeters or larger in length without preparing the surface of the controlled parts. It is shown that the kinetic dependences of the accumulation of operational defects in the parts of tractor units in the analyzed range of service life are monotonically increasing, which can be described by exponential functions with a sufficiently high reliability. It is noted that the obtained dependences are similar to the kinetic dependences of the accumulation of static and dynamic (fatigue) damage obtained as a result of laboratory tests of samples of construction materials, which allows to use approaches to the criteria of the limit state of laboratory samples due to the power load to establish the boundary life of mobile agricultural machinery. However, the kinetics of the intensity of the occurrence of operational cracks in the array of tractor parts is not monotonous and has a maximum in the range of about 11-13 years of operation. This service life can be used as a criterion to stop the operation of the tractor, to carry out defectoscopy of parts and to replace defective parts. With such a long service life of the tractor, there is the greatest probability of sudden destruction of the tractor components and the creation of emergencies.

Optimization methods of operating costs on road transport in international transportation

Transport processes research are closely related to the economic and operational performance of road transport. During planning road transportation, the most important factor is the transport services cost. Known fact that most of the transportation costs are car fuel. The share of car fuel in the transport tariff cost can be 25-50% (depending on the working conditions of vehicles). Therefore, research that is associated with improving the vehicles efficiency by reducing variable costs is appropriate and relevant. The article presents the results of research on the planning of transport processes in the road transport performance in international road transport for the return flight and calculating methods the demand for the amount of fuel purchased in different countries with different prices. The author presents the results of theoretical and experimental research the adequacy of the mathematical model (methodology). The specified mathematical model consists in substantiation of a technique of calculation of quantity of car fuel, definition of the variable factors influencing volumes of fuel expenses, calculation of correction factors (total) received on the basis of technical and operational indicators of vehicles and the influencing factors connected with features of road transport work. . The second part of the research contains the results of the development of an algorithm development to calculate the total cost of automotive fuel, which was purchased at different prices in several countries. Thus, the main purpose of research is the task of substantiating the algorithm (mathematical model – methodology) for determining fuel costs by the criterion of the highest use of fuel in countries at the lowest prices.

Adaptability of reliability of seeding device with dispenser of directed action as direction of resource saving

The article analyzes the application of the latest technologies of precision seeding on the example of the use of a seeding machine with a directional metering unit. To do this, we analyzed such a parameter in agricultural production as the cost of sowing material, which affects its effectiveness. The object of the study is a sowing machine with a directional dispenser, an innovative design solution which will improve agricultural production on the basis of resource conservation. As a result of using a new design solution of the dispenser, the accuracy of the technological process of forming a regular single-grain flow is increased. The connection between the distance from the seed to the cell and the force of its suction is established. The equation of dynamics of movement of seeds and time of exposure of seeds with a cell is received. The analysis of the forces acting on the seeds when moving them by the dispenser of the directed action is carried out. Rational phases of work of the sowing device with the batcher of the directed action are substantiated and parameters of its work are defined.

Justification of permissible deviation of performance of technological operations in process of feeding animals

The issues of implementation of technological processes of preparation and distribution of feed mixture, according to the schedule of technological operations of the livestock complex are considered. The processes of preparation and distribution of the feed mixture are largely influenced by natural and climatic conditions, and accordingly, the daily performance of technological operations has certain deviations in time according to the routine of the livestock complex. One of the features of the processes of preparation and distribution of the feed mixture is the movement of the feed preparation unit between the feed storages under various weather conditions that affect the speed of the unit. Based on the results of evaluating the delay in the execution of technological operations in the preparation and distribution of the feed mixture, using the method of mathematical modeling, the influence on the productivity of animals was determined, justified optimal, from the point of view of zootechnical requirements, delay intervals in the execution of operations in which animals do not lose productivity and ways of their compensation are proposed when performing technological processes. The results of literary studies indicate that a delay in the distribution of the feed mixture for more than 10 minutes leads to a rapid increase in the loss of milk production of animals, and the time for their recovery is about 4-5 days. On the basis of the studies carried out, it has been proved that it is possible to compensate for the delays in the execution of technological operations of the preparation and distribution of the feed mixture by the time that falls on the mixing of the feed components, and can be partially or completely reduced, (provided that transportation operations are performed simultaneously, from the last load of the feed component and mixing). The calculation of the maximum deviation in the execution of the processes of preparation and distribution of the feed mixture, carried out by the method of mathematical modeling, determined that the maximum duration of the delay, taking into account the time to which the animals do not react, can be 22-27% of the preparation time of the feed mixture.

Terms of repair works and forecasting of terms of service of contacts of disassembly type in conditions of incomplete of output information

Collapsible contact joints are the most numerous elements of electrical installations. The efficiency of the contacts, their reliability to a large extent depends on the modes of electric current and temperature, contact pressure, etc. Modification of modes and operation time lead to an increase in the resistance of the contacts, the temperature of their heating and possible thermal destruction. Traditional means for controlling the pressure in the contacts when changing the temperature regime are steel plate springs. Previous investigations have established that these means only partially solve the problem of regulation of contact pressure. An alternative to traditional means is the innovative development of dynamic pressure control tools based on the use of functional alloys with the shape memory effect. The mathematical analysis of terms of carrying out repair works and service life of collision type contacts with the use of probability theory in the conditions of incompleteness of the initial information is carried out. The research substantiates that the use of dynamic method of control of the thermomechanical regime of collapsible contacts allows to stabilize pressure and extend the life of collapsible contacts by 3-4 times.

Modeling of soil tilling and planting unit

This research is aimed at increasing the efficiency of the technical and technological process of small-seeded green manure crops sowing by combining technological operations of a soil-tilling and planting unit (STPU) and improving the design parameters of the scatterer. A scheme of a soil-tilling and planting unit with a scatterer and a control means is proposed, and a concept of the functioning of the technological process of a soil-tilling and planting unit is determined. To study the technological process of small-seeded crops sowing, which is implemented by the STPU, it is important to build a mathematical model of the dynamics of the process for further optimization of both the process itself and the parameters of the sowing apparatus. The simulation includes the development of a model of the dynamics of the STPU travel on the field, taking into account the corresponding traction and resistance forces, the turning moments and the moments of resistance to turning of the tractor, as well as the calculation of the parameters of the seed output from the seed hopper, the dynamics of its travel in the seed tubes to the point of contact with the scatterer and the seed scattering formula on the soil after exiting the seed tubes. The obtained models allow us to determine the technical parameters of various working devices included in the STPU, from the point of view of their compliance with the activities for the quality of the task. The main attention is focused on determining the design parameters of STPU elements based on the construction and research of relevant mathematical models and calculation expressions. In this direction, a study was carried out to determine the optimal components: geometric design parameters and the angular velocity of the seed roller (wк), the initial seed speed in the seed tubes specified by the compressor fan (Vcf), the angle of inclination of the diffuser plate (β) and its height above the soil surface (Hs)) An advanced mathematical model allows you to simulate tillage and sowing units with different working widths.

Improvement of total running time and wear resistance of tillage tools

On the basis of a system analysis of methods of total running time and wear resistance improvement of tillage tools it has been found that in 90% of cases their improvement is achieved by technological methods. In its turn, it requires the use of expensive hardening materials that results in production cost increase of final output. The solution to a problem cannot be based on using one group of methods, it requires a complex approach when using a range of available groups of methods. Correspondingly, the purpose of the research is to identify experimentally some feasible methods of total running time and wear resistance improvement of tillage tools with due regards to soil and climatic conditions of their operation. On the basis of soil and climatic conditions of tillage tools operation, the research identifies experimentally some operational, constructional and technological methods of wear resistance improvement of share and disk tools. The research results have been introduced at the agrarian enterprises of Zhytomyr oblast.