scholarly journals GENERAL STRUCTURE OF TILLAGE DRAFT FORCE. CONSEQUENCES IN EXPERIMENTAL AND APPLICATIVE RESEARCHES

2019 ◽  
Vol 59 (3) ◽  
pp. 253-262
Author(s):  
P. Cardei ◽  
S.L. Muraru ◽  
R. Sfiru ◽  
V. Muraru
Keyword(s):  
General Structure ◽  
Soil Tillage ◽  
Resistance Force ◽  
Agricultural Machinery ◽  
Deformable Solids ◽  
Force Structure ◽  
Simple Generalization ◽  
Mechanics Of Deformable Solids ◽  
Draft Force ◽  
Agricultural Machines

The empirical and theoretical estimation of the draft force of agricultural machinery for soil tillage, has been the target of scientific research for about one hundred years. The results obtained so far may seem contradictory or divergent. The article presents the results of some research on the usual calculation formulas of the draft force of agricultural machines for soil tillage. Although apparently these formulas are different, analyzing the structure of the formula, we find cohesion and coherence embodied in a simple generalization and easy to use both theoretical and experimental. Moreover, the formulas are convertible between them, the two languages used for their definition (the mechanics of deformable solids and that of the phenomenological description), are only different forms of expression for the same phenomenon. Another problem that is addressed in the research whose results are presented in this article is that of highlighting the dependence of the draft force on the tool speed (in the field) of the soil tillage machine. Exposure is complemented by an algorithm that highlights the dependence of the draft force on the tillage tool speed. Also like a consequences of the draft tillage force structure, finally, a third problem addressed in these researches and whose results and perspectives are given in this paper is that of optimizing the working processes of agricultural machinery for soil tillage. The treatment of the problem starts from the hypothesis of the most general formula of the traction resistance force and proposes some ways to solve the optimal problem.

Strategies of maintenance and repair of agricultural machinery

2020 ◽  
pp. 38-48
Author(s):  
Aleksey S. Dorokhov ◽  
Aleksandr V. Denisov ◽  
Aleksey A. Solomashkin ◽  
Valeriy S. Gerasimov
Keyword(s):  
Wear Rate ◽  
Technical Condition ◽  
Research Purpose ◽  
Agricultural Machinery ◽  
Maintenance And Repair ◽  
Wear Rates ◽  
Urgent Task ◽  
Machine Parts ◽  
Current Value ◽  
Agricultural Machines

Modern machines are subject to progressive wear that occurs at different rates, which leads to unpredictable failures that reduce the reliability and durability of machines. The strategy of maintenance and repair is aimed at eliminating these problems. (Research purpose) The research purpose is in analyzing the basic principles of the strategy of maintenance and repair of agricultural machinery in order to ensure control of the technical condition of machine parts. (Materials and methods) When resource diagnostics is used, , the allowable value of the parameter is set in advance for a part . This value is the tolerance that corresponds to a certain wear rate of the part. The tolerance is set based on the condition that if the current value of the controlled resource parameter during the next diagnosis is less than the set value, then such a part at the current value of the wear rate can be finalized until the next inter-control check. Taking into account the wear rate of the same type of parts from the group when determining the allowable wear during their resource diagnostics becomes an urgent task. (Results and discussions) As a result of research, the article presents "Methodology for determining the main indicators of reliability of parts of agricultural machines with different wear rates" and "Methodology for determining the tolerance system of parts of agricultural machines with different wear rates". (Conclusions) The article presents the tolerance system that reduces the probability of failure of machine parts in operation. During resource diagnostics, those parts whose resource parameters exceed the tolerance are rejected.

scholarly journals The least-squares collocation method in the mechanics of deformable solids

2021 ◽  
Vol 1715 ◽  
pp. 012029
Author(s):  
Sergey Golushko ◽  
Vasily Shapeev ◽  
Vasily Belyaev ◽  
Luka Bryndin ◽  
Artem Boltaev ◽  
...  
Keyword(s):  
Least Squares ◽  
Collocation Method ◽  
Least Squares Collocation ◽  
Deformable Solids ◽  
Mechanics Of Deformable Solids

scholarly journals Applications of Discrete Element Method in the Research of Agricultural Machinery: A Review

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 425
Author(s):  
Hongbo Zhao ◽  
Yuxiang Huang ◽  
Zhengdao Liu ◽  
Wenzheng Liu ◽  
Zhiqi Zheng
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Agricultural Machinery ◽  
Design And Optimization ◽  
Design Of Agricultural Machinery ◽  
Agricultural Materials ◽  
Operational Processes ◽  
Dem Model ◽  
Agricultural Machines ◽  
Element Method

As a promising and convenient numerical calculation approach, the discrete element method (DEM) has been increasingly adopted in the research of agricultural machinery. DEM is capable of monitoring and recording the dynamic and mechanical behavior of agricultural materials in the operational process of agricultural machinery, from both a macro-perspective and micro-perspective; which has been a tremendous help for the design and optimization of agricultural machines and their components. This paper reviewed the application research status of DEM in two aspects: First is the DEM model establishment of common agricultural materials such as soil, crop seed, and straw, etc. The other is the simulation of typical operational processes of agricultural machines or their components, such as rotary tillage, subsoiling, soil compaction, furrow opening, seed and fertilizer metering, crop harvesting, and so on. Finally, we evaluate the development prospects of the application of research on the DEM in agricultural machinery, and look forward to promoting its application in the field of the optimization and design of agricultural machinery.

scholarly journals Approaches to the robotization of agricultural mobile machines

2018 ◽  
Vol 161 ◽  
pp. 03014 ◽  
Author(s):  
Vladimir Serebrenny ◽  
Madin Shereuzhev ◽  
Ivan Metasov
Keyword(s):  
High Precision ◽  
Modern Technology ◽  
The State ◽  
Agricultural Machinery ◽  
Factors Affecting ◽  
Technological Processes ◽  
Autonomous Machines ◽  
Autonomous Movement ◽  
Technical Solutions ◽  
Agricultural Machines

Agriculture is the extremely important and developing economic movement in all times. Automation of agricultural machines occurs by different ways. One way is through the creation of specialized technical solutions for the required technological processes, another way is the construction of automatic agricultural machines, including mobile ones. The state of modern technology allows to create autonomous machines. The agriculture robotization trends are the high precision and unmanned farming. The article considers the issues of robotization of agricultural machinery. Stages of robotization of agricultural mobile machines were analyzed. The factors affecting the autonomous movement of mobile agrorobots were shown.

scholarly journals V-belt transmissions of agricultural machines

2021 ◽  
Vol 1 (3) ◽  
pp. 31-36
Author(s):  
N.P. Balovnev ◽  
◽  
Y.I. Brovkina ◽  
L.A. Dmitrieva ◽  
◽  
...  
Keyword(s):  
Shock Loading ◽  
Open Circuit ◽  
Operating Conditions ◽  
Special Method ◽  
Agricultural Machinery ◽  
Belt Drives ◽  
Regulatory Documents ◽  
Guide Roller ◽  
Positive Effect ◽  
Agricultural Machines

The article is devoted to the analysis of design features and operating conditions of V-belt trans-missions of agricultural machinery. When designing these gears, it is recommended to give prefer-ence to gears made according to an open circuit or with a tension roller located outside the belt con-tour, to avoid cross and semi-cross gears, as well as multi-pulley gears with crossing shaft axles. To make the wider use of more progressive types of belts. It was shown that the features of V-belt transmissions of agricultural machinery require clarification of the methods for calculating trans-missions with progressive types of V-belts and automatic belt tensioning methods. It was noted that special attention should be paid to transmissions with multi-profile belts, which calculation has not been sufficiently reflected in domestic regulatory documents. The advantages of such belts are es-pecially noticeable under variable and shock loading. Based on the analysis, the recommendations for clarifying the calculation of belt drives with multi-profile belts were given. Analytical dependencies are proposed for determining the value of the nominal power transmitted by one belt (stream) of a multi-profile belt, allowing automation of the calculation of V-belt transmissions of agricultural machinery. For gears with a tension or guide roller that add an extra (sometimes reverse) bend of the belt, it is proposed to determine the coeffi-cient taking into account different degrees of bending on the pulleys according to a graph built tak-ing into account the linear hypothesis of summation of damages. It is recommended to calculate gears with spring-loaded tensioning rollers and design tensioning devices for such transmissions using a special method that takes into account the belt tensioning method. At the same time, the required value of the pre-tension of the belt can be significantly re-duced, which will have a positive effect on its resource, without losing the traction capacity of the transmission itself. Expressions are given for finding the value of the pre-tension of belts, both for gears with tension due to the elasticity of the belt, and for gears with spring-loaded tension rollers. Conclusions and directions for further research are formulated.

scholarly journals Technical dynamic capabilities in the opinion of Polish producers from the agricultural machines sector1

Management ◽  
2018 ◽  
Vol 22 (2) ◽  
pp. 264-284
Author(s):  
Bogdan Nogalski ◽  
Przemysław Niewiadomski ◽  
Agnieszka Szpitter
Keyword(s):  
Dynamic Capabilities ◽  
Agricultural Sector ◽  
Manufacturing Companies ◽  
Direct Relation ◽  
Agricultural Machinery ◽  
Empirical Level ◽  
Main Target ◽  
Definition Of ◽  
Agricultural Machines

Summary The main aim of this paper is to develop a model of key technical dynamic capabilities providing implementation flexibility of manufacturing companies of the Polish agricultural sector. Achieving the main target required to formulate sub-targets, to which the following have been included: the query of subject literature remaining in a direct relation to the topic of the research, which, in the authors’ intention, will find its expression in the developed definition of technical dynamic capabilities. At the design level, it is essential to search for the answer to the question: what technical capabilities imply dynamic flexibility of the Polish manufacturers of the agricultural machinery sector?, while, at the empirical level, to prioritize individual technical dynamic capabilities and determine what deficiencies in this area are characteristic for the studied companies.

Influence of Atmospheric Humidity on the Critical Buckling Load of Reinforced Concrete Columns

2021 ◽  
Author(s):  
Kaique Moreira Matos Magalhães ◽  
Reyolando Manoel Lopes Rebello da Fonseca Brasil ◽  
Alexandre de Macêdo Wahrhaftig ◽  
Gustavo Henrique Siqueira ◽  
Iryna Bondarenko ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Relative Humidity ◽  
Concrete Columns ◽  
Buckling Load ◽  
Atmospheric Humidity ◽  
Technical Standards ◽  
Reinforced Concrete Columns ◽  
Critical Buckling Load ◽  
Deformable Solids ◽  
Mechanics Of Deformable Solids

In this paper, an evaluation of the influence of atmospheric humidity on the critical buckling load of reinforced concrete columns is performed. A particular case consisting of a real, extremely slender reinforced concrete pole was taken for the study. The chosen mathematical procedure for calculating the critical load is based on the Mechanics of Deformable Solids due to variations of structure vibration frequency over time. The rheological behavior of concrete related to creep and shrinkage, which illustrates the time-dependent aspect of the problem, was also considered in the analysis following normative recommendations from the Brazilian Association of Technical Standards (ABNT). In order to evaluate value changes of critical buckling loads, different time instants after loading the structure as well as different relative humidity from 0% to 100%, in 10% increments were considered. According to the selected criteria, it was possible to verify that a higher atmospheric humidity decreases the water transport from the interior out to the exterior surfaces of concrete, hence positively influencing structure stiffness. Therefore, the lowest reduction on critical buckling was 41.9% at 100% relative atmospheric humidity, versus the highest 60.7% at 0% relative humidity. A period of 7500 days after loading the structure was considered in the analysis.

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