2/2013
Kocsisné B. M., Frigyik G., Kuzsella L., Kuzsella Lné Koncsik Zs., Szilágyiné Bíró A., Kerekes G.
Trends and plans in heat treatment and surface engineering 3
The TÁMOP project of the University of Miskolc” was launched for creating special scientific schools in different engineering topics. One of such is focused on “Innovative materials processing”, including four R&D groups: three groups are dedicated for various technological processes like welding, heat-treatment and metal forming, while the fourth group focuses on computer aided design and modelling in materials processing technologies. In this paper the research work done in Heat Treatment and Surface Engineering R &D group will be overviewed.
Prém L., Balogh A.
Different types of energy input for resistance spot welding of automotive mild steel sheets 7
During the last twenty years the advanced and ultra high strength steels came to the front in automotive industry. In spite of that fact, mild steel sheets have been applied in a modern car fabrication in proportion of 25 to 30°%. The unalloyed steel elements are exposed to cold forming, which technology influences the weldability of this material. This paper presents some different types of energy input, when these mild steel sheets are spot welded.
Tisza M., Gál G., Kiss A., Kovács P., Lukács Zs.
Computer aided engineering methods in metal forming 11
Within the TÁMOP project a special scientific school is created with the title “innovative materials processing”. There are four R & D groups within the innovative materials processing: three groups in various technological processes like welding, heat-treatment and metal forming, as well as a fourth group on computer aided design and modelling in materials processing technologies. In this paper the research work done in this latter group will be overviewed.
Pálmai Z.
The dynamic examination of an anomaly during the large, fast deformation of steel 15
It may occur occasionally during turning that a metallic deposit, the so-called built-up edge (bue) is formed that dilapidates the surface of the workpiece and shortens tool life. We have observed its effect on chip formation with microscopic techniques and have developed a mathematical model for the process. The laboratory experience confirms the numeric solution of the time delayed autonomous differential equations. This model can be applied to other technologies as well where the undeformed chip thickness varies.
Pálmai Z., Szcs J.
Assessment of cutting tool life by measurement control in series production 19
We aimed at utilizing the data gained during the check of the workpiece size to observe the wear of the tool in series production. We have processed AS2 free cutting steel originating from two production charges by P20 uncoated carbide tool on automatic lathe. We designed the workpiece specifically for this purpose and we have measured the deviation from the nominal measure in the case of each piece. These were converted to wear of corner of the cutting edge and we have assessed their wear curve from which the tool life can be calculated. The results of control measurements of flank wear were in accordance with the calculated data of the wear of the corner of the cutting edge.
Szabó O.
Examination of material removal process in honing 23
The paper examines the possibilities of increasing of material removal rate of honing in case of use of superhard tools. Tool having superhard grains significantly increases performance of chip removal, technological process becomes more stable and increase of tool life is meaningful. The author experimentally examined the effects of increase of grain size, cutting speed, tool pressure on changing of cutting time. The result of this is a two stage honing, in which the first stage assures removing of increased allowance, and the second stage is the final or fine stage which assures the realization of the prescribed accuracy and surface roughness.
Hajdú S., Czibere T., Kalmár L.
Flow pattern analysis in runner of banki turbine 27
The small capacity turbine supplied with double-flow runner by Donat Banki is still being developed and manufactured worldwide which implies that the design problems of the cross-flow turbine still have topicality. The present paper concentrates on two computational methods. The one is to determine the the central streamline of flow within the runner and the other realizes the mapping of the runner blade onto a straight cascade.
Kalmár L.,Hellmann R., Régert T., Vígh V.
Investigation of heat transport procedure in uv led module 31
The paper deals with CFD analysis of the heat transport process caused by High Powered LED (Light Emitting Diode) in UV LED Module. This project is a R&D topic including both the laboratory measurements and the CFD simulations of UV LED Module. This project is the result of the several year- long joint research activities between the University of Aschaffenburg and the University of Miskolc. First, the Module – included one UV LED – is introduced, than the measurement after that main steps of the numerical simulation are discussed. Finally the results of measurement and simulation are compared.
Nagy J., Tolvaj B., Szabó Sz.
The effect of shield condenser pitch on the energy consumption of refrigerators 35
A shield condenser is an increasingly common component in refrigerators and freezers. Starting from the differential equation of conduction of heat, the article examines how to determine the optimum condenser tube pitch, where the energy consumption is at its minimum.
Döbröczöni Á.
Some questions on the development of technical products 39
The developing of the machines as systems and their parts is a complex activity. This article gives some of the results on the fields of the planetary gear drives, eco-design, natural analogies and optimization.
Kamondi L.
Research and development of toothed elements of power trains 43
During the past decades the toothed pairs of elements proved again their unchanged significant role in the power trains. Their functions are the accurate conversion of motion, the greatest load carrying capacity at the least sizes, the conformity to the environments. The paper shows geometric, dynamic and acoustic results on the research fields of gear coupling, free running clutch and pair of gears.
Farkas J.
Application of welded t-stiffeners in the minimum cost design of cellular plates supported at four corners 47
Cellular plates consist of two face plates and a grid of stiffeners welded between them. The cells produce a large torsional stiffness, thus, the cellular plates can be calculated as isotropic ones. In previous studies the author has designed cellular plates with halved rolled I-stiffeners. In the present study these rolled stiffeners are replaced by welded T-stiffeners Constraints on stresses, deflection, stiffeners web buckling and fabrication are formulated. The cost function contents the cost of material, assembly, welding and painting. The optima are found by a systematic search using a MathCAD algorithm. Mass and cost savings can be achieved by using welded T-stiffeners instead of rolled ones.
Kovács Gy.
Fibre reinforced plastic strengthened steel structures 51
Fibre reinforced plastic (FRP) composites are often used in light-weight civil engineering applications due to their unique advantages including their high strength-to-weight ratio and excellent corrosion resistance. In particular, many possibilities of using FRP in the strengthening of concrete, wood and steel structures have been explored. The main aim of the current study is to show the types of FRP strengthening systems, strengthening modes of steel structures and possible failure modes of strengthening systems.
Marcsák Gábor Z.
Developing a web application in JavaFX environment to solve optimization problems 55
Despite the rapid progress of computer technology, there are still a lot of problems that cannot be solved only by raw computational power. The Traveling salesman problem is a bright example of the NP problem class. The utilization of informed search (so-called „heuristic”) algorithms is a possible solution in these situations. On the one hand, compared to non-heuristic algorithms, heuristic strategies require much less computation in order to find potential solutions. In many cases, very difficult problems can be solved with them. On the other hand, they have a disadvantage. There is no guarantee that the optimal solution was found. My goal was to develop an advanced web application, which is a standalone collection of modern heuristic algorithms.
Virág Z., Jármai K.
Optimum design of standard size circular continuous girders 59
Nowadays the optimum design is widely used in engineering practice. The economic crisises always remind of saving. That is why it is important to aim at the best price or just material saving. In the minimum cost design the characteristics of the optimal structural version are sought which minimize the cost function and fulfil the design constraints. Further advance of the optimum design is that it gives a true base to compare the different structure versions. In this study only the material cost is minimalized. The aim of the present study is to apply the optimum design principle for continuous girders.
Bokros I., Siménfalvi Z., Szepesi G., Venczel G.
Analysis of stirred tank reactors 63
This paper details the examination of continuous stirred tank reactors (CSTR) for use in the chemical industry. We investigated the effect of the Bayonet type heat exchanger which is inside of CSTR to the power number and the heat transfer coefficient. We made scale up model to adapt the measured and CFD data to industrial size equipment.
Mannheim V.
Environmental chemical research at the University of Miskolc 67
The environmental protection takes a main place in the processes of the chemical industry. There are green chemistry methods and some other processes for decreasing the quantity of the organic industrial waste. This paper summarises the research work of the Environmental chemical research team at the University of Miskolc. In the past 18 months the research group can set up new information and research results. The Life Cycle Assessment (LCA), the BAT and the green chemistry can play an important role in this research.
Szamosi Z., Siménfalvi Z.
Presentation of the equipments which can do the torrefaction of the agricultural residues and its operational parameters 71
The next article’s aim is to present those equipments which are suitable for the torrefaction. The torrefaction is one of the innovative technologies in biomass pre-treatment. The energy density of the agricultural residues is low, comparing other fuels. The energy density means the energy content referenced to the volume or mass. If we increase that physical property of the biomass we can make economical the transportation and the usage of these materials.
view the complete magazine, download pdf
