Mathematical model for reliability assessment of device for preparation and distribution of animal feed as “man-machine”

The lack of simple analytical physical and mathematical models complicates the investigation of the interaction of tillage working bodies with the soil when designing new structures. To simplify these calculations within the framework of agricultural machinery engineering, it is necessary to use software that integrates the development of agricultural mechanics. The purpose of this study was to model and investigate the interaction of tillage working bodies with the soil using Simcenter STAR-CCM+. For this, the volumetric fluid method and the discrete element method were used. When creating the model, the main physical and mechanical properties of the soil were used. As a result, the simulation of the interaction of the most common tillage working bodies, such as a tooth of a duck-foot cultivator, a disc harrow on an elastic stand, a subsoil cultivator (chisel plough), a mouldboard plough, and a smooth roller, was modelled using volumeof-fluid method and discrete element method. The application of the volume-of-fluid method helped establish a nonprimary flow of the soil relative to the working body, while the discrete element method determined the distributions of velocities and forces of interaction of soil particles. It was found that both proposed methods can be useful for modelling the interaction of the tillage working body with the soil in Simcenter STAR-CCM+. Complementing each other, they create a general picture of the physics of the interaction of the tillage tool with the soil. Using Simcenter STAR-CCM+, the interaction process was visualized and the height of the formed ridges and furrow depths and their location in space were

Section: Methodssupporting

confidence: 52%

Section: Literature Reviewmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Untitled

2023

“…In many countries with developed livestock production, research has been conducted on the technological processes of preparing feed mixtures, improving existing ones and developing modern feed preparation machines (Astanakulov et al, 2020). Studies of the operating characteristics of feed preparation and distribution equipment have shown that, along with the increased load on each feed mixer, many factors cause a significant dispersion of technical and economic use indicators (Khmelovskyi et al, 2020), machine reliability parameters (Ruzhylo et al, 2022), and the durability of working bodies. In this regard, one of the most important criteria for the quality of the operation of feed preparation and distribution equipment is its reliability.…”

Section: Introductionmentioning

confidence: 99%

“…Z. Ruzhylo et al (2022) argued that most guidelines for the use of feed preparation and distribution equipment lack information on the level of machine reliability, limit state criteria, and recommendations for maintaining performance. Alongside stationary feed preparation machines and trailed feed dispensers, cattle farms in Ukraine use self-propelled foreign-made feed preparation and distribution equipment.…”

Section: Introductionmentioning

confidence: 99%

A study of mixer-feeder equipment operational reliability

Nоvitskiy,

Banniy,

Novitskyi

et al. 2023

Modern livestock development trends in the agricultural production structure include the use of feed mixers and distribution equipment. However, a stream of malfunctions and failures is reported for mixer-feeders due to factors that are specific to agricultural enterprises in Ukraine, which reduce the operational reliability of feed mixers and distributors. The study aims to evaluate the quantitative indicators of the in-service reliability of mixer-feeders and develop methods to improve them. The reliability test plan [NMT] was used, which implies a certain number of research objects (N), objects undergoing repair in case of performance loss (M), and tests terminated when the operating time (T) is reached. Initial information was collected and processed, and empirical data on the time between failures of KUHN PROFILE 12.2 DS and PROFILE 14.2 DS mixer-feeders in Ukraine were analysed. The analysis established that the faulty condition of mixers-feeders in the initial operation period is caused by the second complexity group failures. Failures related to the loss of the grinding and mixing mechanism, which limits the average time between failures of the feed mixture and distribution equipment, were identified among the second complexity malfunction group. A statistical analysis of the mixer-feeder failure occurrence was carried out. The failure probability of the grinding-mixing mechanism of the feed mixer was determined to be within the normal distribution law. The main parameters of the given theoretical distribution law were determined by calculation results. The calculations determined that the average time between failures is 3152.0 motor-hours; the standard deviation is 902.6 motor-hours; and the coefficient of variation is 0.40. An average time between failures of the study objects was proved to be consistent with the normal distribution law following Kolmogorov’s agreement criterion. Calculations determined that the average reliability index value, according to the normal distribution law, is within the confidence intervals: 1964.2 motor-hours – lower confidence limit; 4339.8 motor-hours – upper confidence limit. The obtained results may be used to improve the mixer-feeder operational reliability

Logical-probabilistic model of the reliability of means for preparing and distributing fodder

Nоvitskiy,

Banniy,

Novitskyi

2023

Countries with a developed agricultural sector of the economy use modern advances in industry and computer technology in precision animal husbandry. At the current stage of animal husbandry development, both in global practice and in Ukraine, for the preparation of fodder mixtures, means for preparation and distribution of fodder are becoming more and more widespread, which combine the operations of loading, grinding, mixing, transportation and dosed distribution of fodder mixtures. The purpose of the presented article is to assess and ensure the reliability of the operation of the means for preparing and distributing fodder due to the logic-probabilistic modeling of failures of the feed mixture unloading mechanism as a subsystem of the "Man-Machine-Environment" technical system. The results of theoretical and experimental research are a continuation of previous work and are aimed at increasing the efficiency of use and ensuring the reliability of machines and equipment for animal husbandry. The obtained results of theoretical and experimental studies of reliability based on logical-probabilistic modeling of means for preparing and distributing feed as complex technical systems depending on the influence of the components "man-operator", "machine", "environment". The shortest paths of failures and the minimum cross-sections of their prevention for the research objects were analyzed. In order to prevent the failure of the human-operator component of the system, it is necessary to provide sufficient qualification of the personnel, foresee the possible occurrence of errors and ensure their timely elimination. In order to prevent failures of the feed mixture unloading mechanism, it is necessary to timely control and adjust the condition of parts during operation and when restoring performance. It has been established that the probability of failure of the mechanism will be less important, provided that the probability of elimination of failures due to insufficient qualification of the operator and failure of drive parts is 0.2. An increase in the probability of failure of the operator under the condition of insufficient qualification from 0.5 to 0.9 will lead to an increase in the probability of failure as a result of a change in the conveyor tension and the impossibility of adjusting the conveyor tension, and at 0.9 the probability of failure of the mechanism will be 0.046. The practical significance of the results lies in the possibility of investigating the probability of failure of the feed mixture unloading mechanism based on the reliability of the components of the means for preparing and distributing feed, including the hydraulic cylinder, drive parts, and conveyor belts