scholarly journals Estimation of Heat Energy in Regeneration of Agricultural Machine Parts by Welding Methods

2020 ◽  
Vol 24 (3) ◽  
pp. 91-100
Author(s):  
Jerzy Winczek ◽  
Marek Gucwa ◽  
Łukasz Skroński
Keyword(s):  
Unit Volume ◽  
Welded Joint ◽  
Electric Arc ◽  
Heat Energy ◽  
Volumetric Method ◽  
The Other ◽  
Agricultural Machine ◽  
Heat Demand ◽  
Machine Parts ◽  
Agricultural Machines

AbstractIn the paper, the method of calculating the welding energy needed to regenerate parts of agricultural machines by welding (joining) or surfacing (rebuilding, hardfacing) is presented. Problems with the lack of adequacy of the commonly used formula for linear welding energy to the actual amount of heat introduced into the welded joint are discussed. A volumetric approach based on the effective amount of heat generated by the electric arc introduced per unit volume of the weld was proposed. The simplified formulas for volumetric energy are presented. The considerations are illustrated with examples of calculations. The analyzed examples include the use of a computerized stand for geometric measurements of metallographic specimens. The proposed volumetric method of calculating the amount of heat introduced into the welded joint is a more realistic indicator of heat demand than linear energy. On the other hand, based on the volume of the weld (padding weld), it allows to determine the amount of energy needed to regenerate machine parts, including agricultural ones.

scholarly journals Monitoring of conditions of agricultural machines’ parts in operation

2014 ◽  
Vol 60 (Special Issue) ◽  
pp. S57-S65 ◽  
Author(s):  
P. Polák ◽  
R. Mikuš ◽  
V. Kročko
Keyword(s):  
Agricultural Production ◽  
Livestock Production ◽  
Operating Conditions ◽  
Vegetable Production ◽  
Agricultural Machine ◽  
Machine Parts ◽  
Agricultural Tractors ◽  
Tractor Diesel ◽  
Agricultural Machines ◽  
Agricultural Operation

This contribution focuses on problems of monitoring the runout of tractor diesel motor parts used in agricultural operation. Crankshafts from the agricultural tractors of type Zetor 6911 are used as samples for measuring the runout and circularity. The first sample of the crankshaft is loaded in the tractor used in livestock production, and the second one is used in vegetable production. Measured values of the runout and circularity of both samples are evaluated by tables and polar diagrams. Results of the experiment show the amount of runout and the following wear of agricultural machine parts in different operating conditions of agricultural production.

scholarly journals New method of calculating the amount of heat input to the weld

2020 ◽  
pp. 23-27
Author(s):  
Jerzy Winczek ◽  
Kwiryn Wojsyk
Keyword(s):  
Surface Area ◽  
General Formula ◽  
Fusion Zone ◽  
Heat Input ◽  
Unit Volume ◽  
Welded Joint ◽  
Unit Length ◽  
Welding Process ◽  
Electric Arc ◽  
New Method

A new method of calculating the amount of heat introduced into the welded joint is presented. Instead of the previously used measure of heat input per unit length, heat input per unit volume was proposed. The proposed method and general formula are based on the basic technological parameters of the welding process (i.e. energy generated by the electric arc and welding speed) and the cross-sectional area of the fusion zone in the welded joint. A simplified method of calculating heat input per unit volume is presented by using simple formulas to calculate the surface area of the fusion zone in cross-section of the weld for the most common shapes in classic welding methods. The proposed general formula allows for a more accurate way of calculating the heat input per unit of volume depending on the the energy generated by the electric arc (e.g. for pulse current) and the surface area of the reinforcement and fusion zone using other direct measurement methods.

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 Optimization of cutting conditions using artificial neural networks and the Edgeworth-Pareto method for CNC face-milling operations on high-strength grade-H steel

2019 ◽  
Vol 105 (5-6) ◽  
pp. 2151-2165 ◽  
Author(s):  
Adel Taha Abbas ◽  
Danil Yurievich Pimenov ◽  
Ivan Nikolaevich Erdakov ◽  
Tadeusz Mikolajczyk ◽  
Mahmoud Sayed Soliman ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Unit Volume ◽  
High Strength ◽  
Face Milling ◽  
Production Costs ◽  
The Other ◽  
Cutting Conditions ◽  
Milling Operations ◽  
Artificial Neural ◽  
Pareto Method

Abstract Computer Numerical Control (CNC) face milling is commonly used to manufacture products from high-strength grade-H steel in both the automotive and the construction industry. The various milling operations for these components have key performance indicators: accuracy, surface roughness (Ra), and machining time for removal of a unit volume min/cm3 (Tm). The specified surface roughness values for machining each component is achieved based on the prototype specifications. However, poor adherence to specifications can result in the rejection of the machined parts, implying extra production costs and raw material wastage. An algorithm using an artificial neural network (ANN) with the Edgeworth-Pareto method is presented in this paper to optimize the cutting parameter in CNC face-milling operations. The set of parameters are adjusted to improve surface roughness and minimal unit-volume material removal rates, thereby reducing production costs and improving accuracy. An ANN algorithm is designed in Matlab, based on a 3–10-1 Multi-Layer Perceptron (MLP), which predicts the Ra of the workpiece surface to an accuracy of ± 5.78% within the range of the experimental angular spindle speed, feed rate, and cutting depth. An unprecedented Pareto frontier for Ra and Tm was obtained for the finished grade-H steel workpiece using an ANN algorithm that was then used to determine optimized cutting conditions. Depending on the production objective, one or the other of two sets of optimum machining conditions can be used: the first one sets a minimum cutting power, while the other sets a maximum Tm with a slight increase (under 5%) in milling costs.

Aspects of comparative lung growth

1952 ◽  
Vol 140 (900) ◽  
pp. 432-441 ◽  
Keyword(s):  
Surface Area ◽  
Lung Volume ◽  
Unit Volume ◽  
Structural Complexity ◽  
Internal Surface ◽  
The Other ◽  
Lung Growth ◽  
Normal Numbers ◽  
Elastic Fibres ◽  
Internal Surface Area

In this paper, the general principles of lung growth already worked out in the rabbit (Short 1950) have been examined in the human lung. Using the same methods, a similar series of measurements have been made in embryonic and post-natal human lungs. Structural complexity has been measured in terms of internal surface area per unit volume of lung. Further support has been found for believing that the structural complexity of the lung is the result of tension in elastic fibres. At all stages of development a linear relationship similar to that found in the rabbit has been demonstrated between structural complexity of the lung on the one hand and a factor representing tension in elastic fibres (lung volume/interstitial volume) on the other. During the period of embryonic development, the structural complexity of the lungs of man and the rabbit is in very close agreement. It has also been found that the structural complexity per unit volume of the lungs at term in the mouse, rat, rabbit and man is the same. This suggests that the range of growth, between lung bud and term (responsible for the physical forces acting on elastic fibres and thus increasing the structural complexity), is the same in these four species. In man and the rabbit there are grounds for believing that the range of growth is indeed the same. Direct measurement of the volume of the lung rudiment at a stage when the tracheal bud has divided into two lumina in these two species shows them to be of the same order of size. Since the unit volumes at term are equal, the range of growth is equal in both species; a circumstance which accounts satisfactorily for the fact that the structural complexity at term is also the same in man and the rabbit. Calculation has also been made of the age at which formation of septa stops. In the two small species, the mouse and rat, the complexity of lung architecture probably increases throughout the post-natal period of growth. In the rabbit, differentiation is certainly complete by the third month of life, and in man is probably completed during the second year of life. Thereafter, continued growth of lung volume is accompanied by simple distension of the existing architecture. Further evidence bearing on growth and differentiation has been obtained from grossly hypoplastic lungs. In three cases of diaphragmatic hernia involving reduction of lung volume to one-sixth or less of normal size, structural complexity was found to be normal. Moreover, lobular size was also normal. Had the normal numbers of lobules been formed, their size must necessarily have been reduced. Therefore, reduction in total number of lobules and in total lung volume is not accompanied by structural hypoplasia of those lobules which are formed. The estimate of internal surface area per unit volume of lung in the adult mouse, rat, rabbit and man has been shown to increase as the smaller species are approached. On the other hand, the ratio of total internal surface area of the lung to body weight of these four species is probably to be regarded as a constant.

scholarly journals Selection of Materials and Technology for Forming the Layers Resistant to Abrasive Wear

2010 ◽  
Vol 18 (28) ◽  
pp. 59-68
Author(s):  
Silvia Revesová ◽  
Pavel Blaškovitš
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Life Extension ◽  
Wear Resistant ◽  
Suitable Material ◽  
Agricultural Machine ◽  
Machine Parts ◽  
Selection Of

Selection of Materials and Technology for Forming the Layers Resistant to Abrasive Wear This article deals with the selection of materials for forming wear resistant layers within agricultural machine parts wear. We can achieve required hardness, wear resistance and life extension of agricultural machine parts and tools by the selection of a suitable material and surfacing technology.

scholarly journals Numerical and Experimental Investigations of Fracture Behaviour of Welded Joints with Multiple Defects

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4832
Author(s):  
Mihajlo Aranđelović ◽  
Simon Sedmak ◽  
Radomir Jovičić ◽  
Srđa Perković ◽  
Zijah Burzić ◽  
...  
Keyword(s):  
Yield Stress ◽  
Welded Joints ◽  
Welded Joint ◽  
Numerical Models ◽  
Carbon Steels ◽  
The Other ◽  
Experimental Investigations ◽  
Root Penetration ◽  
Strain Diagram ◽  
Multiple Defects

Current standards related to welded joint defects (EN ISO 5817) only consider individual cases (i.e., single defect in a welded joint). The question remains about the behaviour of a welded joint in the simultaneous presence of several different types of defects, so-called multiple defects, which is the topic of this research. The main focus is on defects most commonly encountered in practice, such as linear misalignments, undercuts, incomplete root penetration, and excess weld metal. The welding procedure used in this case was metal active gas welding, a common technique when it comes to welding low-alloy low-carbon steels, including those used for pressure equipment. Different combinations of these defects were deliberately made in welded plates and tested in a standard way on a tensile machine, along with numerical simulations using the finite element method (FEM), based on real geometries. The goal was to predict the behaviour in terms of stress concentrations caused by geometry and affected by multiple defects and material heterogeneity. Numerical and experimental results were in good agreement, but only after some modifications of numerical models. The obtained stress values in the models ranged from noticeably lower than the yield stress of the used materials to slightly higher than it, suggesting that some defect combinations resulted in plastic strain, whereas other models remained in the elastic area. The stress–strain diagram obtained for the first group (misalignment, undercut, and excess root penetration) shows significantly less plasticity. Its yield stress is very close to its ultimate tensile strength, which in turn is noticeably lower compared with the other three groups. This suggests that welded joints with misalignment and incomplete root penetration are indeed the weakest of the four groups either due to the combination of the present defects or perhaps because of an additional unseen internal defect. From the other three diagrams, it can be concluded that the test specimens show very similar behaviour with nearly identical ultimate tensile strengths and considerable plasticity. The diagrams shows the most prominent yielding, with an easily distinguishable difference between the elastic and plastic regions. The diagrams are the most similar, having the same strain of around 9% and with a less obvious yield stress limit.

scholarly journals AGRICULTURAL MACHINES INJURIES

2009 ◽  
Vol 16 (04) ◽  
pp. 485-488
Author(s):  
MUHAMMAD AKRAM ◽  
MUHAMMAD NAZIM ◽  
MUHAMMAD REHMAN GULZAR ◽  
Javed Iqbal
Keyword(s):  
Lower Limb ◽  
Young Male ◽  
Descriptive Study ◽  
Male Population ◽  
Surgical Department ◽  
Agricultural Machine ◽  
Agricultural Injuries ◽  
Degloving Injuries ◽  
Age And Sex ◽  
Agricultural Machines

O b j e c t i v e s : (1) To determine the extent of agricultural injuries in term of their site, severity, management and type ofagriculture machine. (2) To determine the techniques that can decrease the morbidity and mortality caused by agricultural injuries. S t u dyd e s i g n : Descriptive study. S e t t i n g : This study was conducted in surgical department of Allied & DHQ hospital Faisalabad. P e r i o d : January2007 to December 2007. Material a n d M e t h o d s : This descriptive study was performed in 40 consecutive patients in surgical departmentDHQ/Allied hospital Faisalabad during Jan.2007 to Dec.2007.AII people who got agricultural injuries were included. People who got traumaticinjuries other than agricultural machines were excluded. All injuries were noted with respect to the age and sex of the patient, site, size, andseverity of injury, and type of agricultural machine. Management was done accordingly. Result: Out of 40 cases, 34 [85%] were male and06[15%] were female. In 25 cases [67.5%] fodder cutter were involved. In 10 cases[25%]pinching machines [gears, belt, chain machines] wereinvolved .03 cases [7.5%]run over by machine. 02 cases [05%]by harvesting machines In 30 cases[75%]upper limb was involved. In 05 [12.5%]cases scalp injuries were noted. In 02 cases [05%] genitalia were avulsed. In 03cases [7.5%] lower limb was involved. Injuries range from simplelacerations, degloving injuries, tendons &vessels injuries &finally amputations. C o n c l u s i o n : Mostly young male population is involved inagricultural machine injuries. Morbidity of .agricultural machine injuries can be reduced by modifying design of agriculture machines, by trainingfarm workers & by their proper treatment.

scholarly journals Theoretical background for the creation of wear-resistant coatings at the carbo-vibro-arc hardening

2021 ◽  
Vol 341 ◽  
pp. 00032
Author(s):  
Aleksandr Kolomeichenko ◽  
Nikolay Titov ◽  
Aleksеy Kolomeichenko
Keyword(s):  
Electric Field ◽  
Hardened Layer ◽  
Theoretical Background ◽  
Electric Arc ◽  
Theoretical Studies ◽  
Carbon Electrode ◽  
Metal Coatings ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Machine Parts

The paper presents the results of theoretical studies that allow predicting the formation of wear-resistant coatings on the working surfaces of machine parts by the method of carbo-vibro-arc hardening (CVAH). Analytical regularities of electric field intensity formation by oscillating carbon electrode during carbo-vibro-arc hardening (CVAH) have been established; the maximum layer thickness of multicomponent paste, 2.1...2.5 mm, which ensures stable electric arc combustion during CVAH, has been theoretically substantiated. With the increase of amplitude and frequency of oscillations of the carbon electrode, the electric field strength at CVAH decreases nonlinearly, but the thickness of the hardened layer of the multicomponent paste has the greatest influence on it. As a result, ceramic-metal coatings of high quality and integrity are formed on the hardened surfaces of parts. The testing of the obtained theoretical regularities has confirmed their reliability.

scholarly journals Radiation Shielding Property of Concrete Using Electric Arc Furnace Oxidizing Slag Aggregate

2016 ◽  
Author(s):  
Han-Seung Lee ◽  
Hee-Seob Lim ◽  
Jae-Seok Choi
Keyword(s):  
Physical Properties ◽  
Unit Volume ◽  
Gamma Ray ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Radiation Shielding ◽  
X Rays ◽  
Arc Furnace ◽  
Normal Concrete ◽  
Volume Weight

Electric arc furnace oxidizing slag (EAF) has a high density of 3.0~3.7 t/m3 and therefore has a high bulk density when mixed with concrete. Extensive research has been conducted on the use of concrete with high unit volume weight as heavyweight concrete for radiation shielding concrete. In this study, to examine the possibility of developing a radiation shielding concrete, the physical properties of normal concrete, magnetite concrete, EAF concrete, and EAF concrete with added iron powder, were compared. Also, their radiation shielding performance was assessed through shielding tests against X-rays and γ-rays. While the unit volume weight of EAF concrete (3.21 t/m3) appeared lower than that of magnetite concrete (3.5 t/m3), the compressive strength of EAF concrete was greater than those of magnetite and normal concretes. The radiation shielding ratio of magnetite concrete was observed to be 93.9% from the X-ray shielding test, followed by 91.2% of EAF concrete, and 73.7% of normal concrete, indicating a linear relationship with unit volume weight. From the γ-ray shielding test, the performance of EAF and magnetite concretes appeared to be similar. Based on the excellent physical properties and radiation shielding performance of EAF concrete, its potential applicability as radiation shielding concrete was confirmed.

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