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1

Experimental Verification of the Cast Iron Solidification Model

Mendakiewicz Jerzy

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 3

91--94

EN

The article concerns the experimental verification of the numerical model simulating the solidification and cooling processes proceeding in the domain of cast iron casting. The approximate course of the function describing the evolution of latent heat and the value of substitute specific heat resulting from its course were obtained using the thermal and derivative analysis (TDA) method The TDA was also used to measure the cooling curves at the distinguished points of the casting. The results obtained in this way were compared with the calculated cooling curves at the same points. At the stage of numerical computations, the explicit scheme of the finite difference method was applied. The agreement between the measured and calculated cooling curves is fully satisfactory.

2

Optimization of Ferrite Stainless Steel Mechanical Properties Prediction with artificial Intelligence Algorithms

Honysz R.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 2

749-753

EN

The article presents a computational model build with the use of artificial neural networks optimized by genetic algorithm. This model was used to research and prediction of the impact of chemical elements and heat treatment conditions on the mechanical properties of ferrite stainless steel. Optimization has allowed the development of artificial neural networks, which showed a better or comparable prediction result in comparison to un-optimized networks has reduced the number of input variables and has accelerated the calculation speed. The introduced computational model can be applied in industry to reduce the manufacturing costs of materials. It can also simplify material selection when an engineer must properly choose the chemical elements and adequate plastic and/or heat treatment of stainless steels with required mechanical properties.

3

Prediction optimization of mechanical properties of ferrite stainless steels after forging treatment with use of genetic algorithms

Honysz R.

Archives of Materials Science and Engineering

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2019

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Vol. 100, nr 1/2

13--20

EN

Purpose: The paper describes the use of artificial neural networks to research and predict the effect of chemical components and thermal treatment conditions on stainless steel's mechanical characteristics optimized by genetic algorithm. Design/methodology/approach: The quantity of input variables of artificial neural networks has been optimized using genetic algorithms to enhance the prediction quality of artificial neural network and to enhance their efficiency. Then a computational model was trained and evaluated with optimized artificial neural networks. Findings: Optimization, with the exception of tensile strength, has enabled the creation of artificial neural networks, which either showed a better or similar performance from base networks, as well as a decreased amount of input variables As a consequence, noise data is decreased in the computational model built with the use of these networks. Research limitations/implications: Data analysis was required to confirm the relevance of obtaining information used for modelling to use in training procedures for artificial neural networks. Practical implications: Using artificial intelligence enables the multi-faceted growth of stainless steel engineering, even though there is only a relatively small amount of descriptors. Built and optimized computational model building using optimized artificial neural networks enables prediction of mechanical characteristics after normalization of forged ferritic stainless steels. Originality/value: In order to decrease production expenses of products, an introduced model can be obtained in manufacturing industry. It can also simplify the selection of materials if the engineer has to correctly choose chemical elements and appropriate plastics and/or heat processing of stainless steels, having the necessary mechanical characteristics.

4

Mathematical model for determining the expenditure of cooling and lubricating fluid reaching directly the grinding zone

Stachurski W., Sawicki J., Krupanek K., Midera S.

Archives of Materials Science and Engineering

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2018

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Vol. 94, nr 1

27--34

EN

Purpose: The purpose of this article is to discuss the method of determining the mathematical model used for calculating the amount of emulsion reaching directly the grinding zone during the hob sharpening process. Design/methodology/approach: The mathematical model, in the form of a multiple regression function, was determined based on the acceptance and rejection method. The data for the calculations was obtained by conducting numerical simulations of fluid flow in the Ansys CFX software. Findings: A mathematical model enables calculating the amount of efficient expenditure of emulsion reaching directly the zone of contact between the grinding wheel and workpiece (hob cutter rake face) at various nozzle angle settings and different nominal expenditures of emulsion. The verification of the mathematical relationship confirmed its accuracy. Research limitations/implications: Further research should focus on the other types of grinding process and other types of cooling and lubricating fluids. Practical implications: The mathematical model enables a selection and application in the workshop and industrial practice of various variants of emulsion supply during the grinding of hob cutter rake face. Analysis of the multiple regression equation created on the basis of the acceptance and rejection method also allows predicting changes in the analyzed numerical model. Originality/value: The literature review has shown that no research of this type has been conducted with regard to analyses and optimisation of the grinding process during hob cutter sharpening. The results of this research are a novelty on a worldwide scale.

5

Application of the Finite Elements Method for computer simulation of properties of surface layers

Śliwa A.

Archives of Materials Science and Engineering

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2017

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Vol. 86, nr 2

56--85

EN

Purpose: The work presents the application of the Finite Elements Method in a computer simulation whose aim is to determine the properties of PVD and CVD coatings on various substrates and to optimise parameters of a laser surface treatment process of surface layers of tool steels. Design/methodology/approach: The article discusses the application of the finite elements method for simulating the determination of stresses and microhardness of Ti+TiN, Ti+Ti(CN) and Ti+TiC coatings obtained in a magnetron PVD process on a substrate of sinter high-speed steel, of Ti/Ti(C,N)/CrN, Ti/Ti(C, N)/(Ti, Al)N, Ti/(Ti, Si)N/(Ti, Si)N, Cr/ CrN/CrN, Cr/CrN/TiN and Ti/DLC/DLC coatings obtained in a PVD and CVD process on magnesium alloys, of graded and monolayer coatings (Ti, Al)N, Ti(C,N) produced with the PVD arc technique on a substrate of sintered carbides, cermets and oxide tool ceramics and tool steel remelted and alloyed with a high-performance diode laser (HPDL). Modeling of stresses was performed with the help of finite element method in ANSYS and MARC environment, and the experimental values of stresses were determined based on the sin2Ψ. Findings: The models presented satisfy the assumed criteria, and they can be applied for the determination of properties of surface layers and optimisation of PVD and CVD processes and laser alloying and remelting. The results of a computer simulation correlate with experimental results. The models developed allow to largely eliminate costly, timeconsuming and specialist experiments which have to be done during investigations for the benefit of computer simulations. Research limitations/implications: To be able to assess the possibility of application of surface layers, a computer simulation of other properties of coatings has to be additionally carried out, and a strength analysis has to be made of other coatings coated onto various substrate materials. Originality/value: value Computer simulation and modelling is an interdisciplinary field necessary for the development of science and technology, enabling to perform direct visualisation of properties, which cannot be identified in experimental observations. The purpose of computer simulation and modelling is to improve the ability to predict results and to optimise solutions.

6

Computer Simulation of the Relationship between Selected Properties of PVD Coatings

Śliwa A., Kwaśny W., Sitek W., Bonek M.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2A

481--484

EN

The possibility to apply the Finite Element Method to calculate internal stresses which occur in Ti+TiN, Ti+Ti(CxN1-x) and Ti+TiC coatings obtained in the magnetron PVD process on the sintered high-speed steel of the PM HS6-5-3-8 type. For the purpose of computer simulation of internal stresses in coatings with the use of MES, the correct model of analyzed specimens was worked out and then it was experimentally verified by comparison of calculation results with the results of computer simulation. Accurate analysis of correlations indicated especially strong dependence between internal stresses and microhardness and between microhardness and erosion resistance what created conditions for establishing the dependence between internal stresses obtained in the result of computer simulation and erosion resistance as basic functional quality of coating. It has essential practical meaning because it allows to estimate predictable erosion resistance of coating exclusively on the base of the results of computer simulation for used parameters in the process of coating manufacturing.

7

2D-Finite element analysis of inlay-, onlay bridges with using various materials

Śmielak B., Świniarski J., Wołowiec-Korecka E., Klimek L.

Archives of Materials Science and Engineering

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2016

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Vol. 79, nr 2

71--78

EN

Purpose: To compare the impact of different bridge constructions and different loads on stress distribution in bridges. Design/methodology/approach: The study was conducted on 96 computer models of both premolars and molars that simulated a missing second premolar restored with a bridge supported on crown inlays or onlays. Simulations were made of a bridge constructed from four different materials: Au alloy, Cr/Ni alloy as well as two kinds of glass fibre-reinforced composites: Targis Vectris and FibreKor /Sculpture. The study was conducted using the finite element method (FEM). The results were analysed with PQStat statistical software version 1.6. Findings: In none of the analysed cases did stresses appear capable of damaging the bridge construction. Reduced stresses were lower in glass fibre reinforced composite materials than in metal alloys. Practical implications: The force application point has a decisive influence on stress distribution in the hard dental tissue and in bridges. The highest stress values occurred at the loading of the pontic tooth. Originality/value: The force application point has a decisive influence on stress distribution in the hard dental tissue and in bridges. The highest stress values occurred at the loading of the pontic tooth.

8

Prediction optimization of mechanical properties of ferrite stainless steels after rolling treatment with use of genetic algorithms

Honysz R.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 68, nr 1

17--24

EN

Purpose: The article discusses the use of artificial neural networks for research and prediction of the impact of chemical elements and heat treatment parameters on the mechanical properties of stainless steels optimized by genetic algorithm. Design/methodology/approach: To improve the quality of artificial neural network models and improve their performance the number of input variables of artificial neural networks has been optimized with use of genetic algorithms. Then a computational model build with optimised artificial neural networks were trained and verified. Findings: Optimization, except of tensile strength Rm case, has allowed the development of artificial neural networks, which either showed a better or comparable result from base networks, and also have a reduced number of input variables. As a result, in computational model constructed with use of these networks the noise information is reduced. Research limitations/implications: Data analysis was needed to verify if obtained data used for modelling are relevant to use them in artificial neural networks training processes. Practical implications: The use of artificial intelligence allows the multifaceted development of stainless steels engineering, even if only a small number of descriptors is available. Constructed and optimised computational model build with use of optimised artificial neural networks allows prediction of mechanical properties of rolled ferritic stainless steels after normalization. Originality/value: Introduced model can be obtain in industry to reduce manufacturing costs of materials. It can also simplify material selection, when engineer must properly choose the chemical elements and adequate plastic and/or heat treatment of stainless steels with required mechanical properties.

9

Określenie stopnia odkształcenia w łukach giętych metodą indukcyjną na podstawie obliczeń numerycznych w stosunku do rzeczywistego procesu kształtowania łuków

Cieśla M., Gontarz A., Hadasik E., Mutwil K., Pater Z., Tomczak J., Kawała T., Rzepka W.

Energetyka

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2014

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nr 4

211--217

PL

W artykule przedstawiono wykorzystanie technik numerycznych do analizy procesów kształtowania plastycznego metali i ich stopów. Projektując nowe technologie, narzędzia i maszyny można już w początkowej fazie prac optymalizować parametry procesu, a często nawet rozwiązania konstrukcyjne, eliminując w ten sposób przynajmniej część prób wdrożeniowych. Jest to szczególnie istotne w przypadku technologii nowych i stosunkowo drogich, gdzie trudno jest przewidzieć końcowy efekt, a każdy popełniony błąd wiąże się z dużymi nakładami finansowymi. Do tego typu procesów można zaliczyć również gięcie indukcyjne rurociągów, w którym koszt materiału wejściowego – rur – liczony jest w setkach tysięcy złotych. Dlatego też w takich przypadkach w pełni zasadne jest prowadzenie przedwdrożeniowych analiz w wirtualnej przestrzeni komputera, które pozwolą na określenie optymalnych parametrów procesów, gwarantujących uzyskanie łuków o wysokich parametrach geometrycznych i wytrzymałościowych, spełniających wymogi stawiane przez Urząd Dozoru Technicznego. Wykorzystując techniki numeryczne zamodelowano proces gięcia łuków rurowych z lokalnym nagrzewaniem giętej rury. W trakcie obliczeń wyznaczono geometrię giętych rur, a także określono rozkłady intensywności odkształceń, naprężeń, temperatur oraz kryterium pękania. Uzyskane wyniki zweryfikowano doświadczalnie w warunkach przemysłowych w Zakładach Remontowych Energetyki Katowice SA.

EN

Presented is the application of numerical techniques for the analysis of metals and their alloys shaping processes. When designing new technologies, machines and tools one can even in the initial stage optimize a process parameters and also often a construction solutions, eliminating in this way at least a portion of implementation tests. It is especially essential in case of new and relatively expensive technologies where it is difficult to predict the final effect and every mistake results in big financial outlays. To such type of processes we can include induction bending where the cost of feed material i.e. pipes is counted in many hundred thousand zlotys. That is why in such cases it is reasonable to carry out pre-implementation analyses in a computer virtual space which allow determination of optimum process parameters guaranteeing to obtain bends of high geometric and strength parameters and fulfilling all requirements needed by the Technical Supervision Office (UDT). The pipe bending process with local heating of a bended pipe is modelled with the use of numerical techniques. Determined is the bended pipes geometry as well as intensity distributions of deformations, stresses, temperatures and a cracking criterion. The obtained results were empirically tested in industrial conditions in Zakłady Remontowe Energetyki Katowice SA facility.

10

Residual stress development in railroad rails – a parametric study

Pazdanowski M.

Czasopismo Techniczne. Budownictwo

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2014

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R. 111, z. 6-B

83--94

EN

This paper presents the results of a parametric study undertaken to analyse the influence that changes in the material model and contact zone parameters may have on residual stress levels. A simplified shakedown based mechanical model is used to estimate the residual stress distributions due to simulated contact loads. An information on final shakedown state of the rail subjected to given loading program is obtained at a substantially reduced computational cost compared to the standard incremental analysis. A 50% increase in peak contact pressure may increase the longitudinal residual stress level by over 700%. The dependence of peak residual stresses on changes in the hardening ratio is almost linear, while the dependence of peak residual stresses on changes in the yield limit indicates a quadratic relationship. The research indicates that in future applications, a simplified treatment of the rail/wheel interface is justified, as long as the peak pressure in the contact zone is estimated correctly. The residual stresses in rails induced by service conditions may reach very high values, on a par with the material yield limit. This effect is aggravated by the operating procedure of increasing wheel axle loads.

PL

W niniejszym opracowaniu przedstawiono wyniki studium parametrycznego przeprowadzonego w celu zbadania wpływu zmian modelu materiału i parametrów strefy kontaktu na poziom naprężeń resztkowych w szynie kolejowej. Uproszczony model mechaniczny, oparty na teorii plastycznego przystosowania, został zastosowany do oszacowania rozkładu naprężeń resztkowych wywołanych symulowanymi obciążeniami kontaktowymi. Stwierdzono, że 50% wzrost maksymalnego ciśnienia w strefie kontaktu skutkuje wzrostem maksymalnych naprężeń resztkowych o około 700%, przy czym zależność maksymalnych naprężeń resztkowych od zmian współczynnika wzmocnienia materiału szyny ma charakter liniowy, podczas gdy zależność tych samych naprężeń od wartości granicy plastyczności ma charakter kwadratowy. Przeprowadzone obliczenia wskazują, że uproszczone traktowanie strefy kontaktu koło/szyna jest uzasadnione, jak długo maksymalne wartości ciśnienia w tej strefie są oszacowane poprawnie. Naprężenia resztkowe w szynie kolejowej, wywołane przez obciążenia eksploatacyjne kołami taboru, mogą osiągnąć bardzo duże wartości, porównywalne z wartością granicy plastyczności materiału. Efekt ten pogłębia się na skutek zwiększania obciążeń na oś taboru.

11

Mechatronic systems in mining roadheaders - examples of solutions

Jasiulek D., Świder J.

Pomiary Automatyka Robotyka

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2013

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R. 17, nr 1

121-127

EN

In the process of control of mining machines the problems with development of a classical mathematical model describing phenomena that accompany operation of these machines are presented. These problems are the result of specificity of the process of driving the roadways and the direct reason to undertake trials to use artificial intelligence technologies in modelling of phenomena, which occur during rock-drivage of roadways. The following problems are presented in the paper: -state-of-the-art control systems used in roadheaders, -possibilities of use of artificial neural networks in control systems of mining machines (on the example of a roadheader), -model tests with use of data recorded during drivage of roadway with use of a roadheader, -determination of cutting resistance with use of an artificial neural network to determine the value of set angular speed of a roadheader’s cutter jib in the plane parallel to the roadway floor. Presented model tests are the result of R&D projects associated with designing of an intelligent control system of the roadheader, which are realized at the KOMAG Institute of Mining Technology and at the Faculty of Mechanical Engineering of the Silesian University of Technology.

PL

W procesie sterowania maszyn górniczych występuje wiele czynników, utrudniających przygotowanie klasycznego modelu matematycznego, opisującego zjawiska towarzyszące pracy maszyny. Problemy te, wynikające ze specyfiki procesu drążenia wyrobisk, są bezpośrednią przyczyną podejmowania prób zastosowania technik sztucznej inteligencji w modelowaniu zjawisk występujących w trakcie drążenia wyrobisk korytarzowych (tuneli). W artykule zaprezentowano: - badanie stanu wiedzy z zakresu systemów sterowania kombajnów chodnikowych, - możliwości zastosowania sztucznych sieci neuronowych w układach sterowania maszyn górniczych (na przykładzie kombajnu chodnikowego), - wyniki badań procesu drążenia wyrobiska kombajnem chodnikowym, - określenie oporów skrawania z wykorzystaniem sztucznej sieci neuronowej do wyznaczenia wartości prędkości kątowej wysięgnika kombajnu chodnikowego.

12

Identyfikacja parametrów modelu fizycznego materiału lepkosprężystego na podstawie doświadczalnej charakterystyki pełzania

Gnatowska R., Gnatowski A.

Modelowanie Inżynierskie

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2013

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T. 17, nr 48

52--56

PL

Podejmowanie i realizacja prac badawczych nad właściwościami materiałów, jak również nad metodami kształtowania ich właściwości fizycznych i użytkowych to sprawa szczególnie istotna. W dziedzinie tworzenia nowych materiałów dąży się do przewidywania ich właściwości mechanicznych. W oparciu o określoną i trafnie dobraną teorię, można zająć się teoretycznym przewidywaniem właściwości materiałów lepkosprężystych na podstawie znanych cech ich składników. Publikacja dotyczy modelowania matematycznego materiału lepkosprężystego.

EN

Implementation of research on the materials properties, as well as the methods to determine their physical and performance properties is particularly important. In the development of new materials, the aim is to predict their mechanical properties. Based on the theory, we can predict the properties of viscoelastic materials based on characteristics their ingredients. Publication concerns mathematical modeling of viscoelastic material.

13

Properties determination of two-layer coatings deposited by PVD techniques using computer simulation

Śliwa A., Kwaśny W., Dobrzański L.A., Dziwis R.

Archives of Materials Science and Engineering

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2013

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Vol. 63, nr 2

68--74

EN

Purpose: The aim of the research is the computer simulation of the internal stresses in bilayer coatings Ti+TiN and Ti+Ti(C,N) obtained in the magnetron PVD process on the sintered high-speed steel of PM HS6-5-3-8 in working atmosphere including 100% N2, and 50%N250%CH4. Design/methodology/approach: The experimental values of stresses were determined basing on the X-ray diffraction patterns using method sin2Ψ and computer simulation of stresses was carried out in MARC environment, with the help of finite elements method. Findings: The computer simulation results correlate with the experimental results. The presented model meets the initial criteria, which gives ground to the assumption about its usability for determining the stresses in coatings, employing the finite element method using the MARC program. Research limitations/implications: It was confirmed that using of finite element method for estimating stresses in PVD coatings can be a way for reducing the investigation costs Results reached in this way are satisfying and in slight degree differ from results reached by experimental method. However for achieving better calculation accuracy in further researches it should be developed given model which was presented in this paper. Originality/value: Presently the computer simulation is very popular, what allows to better understand the interdependence between parameters of process and choosing optimal solution. The possibility of application faster and faster calculation machines and coming into being many software make possible the creation of more precise models and more adequate ones to reality.

14

FEM and Flow Simulation Module for selecting parameters in rotors flow systems

Lenik K., Korga S., Kozera R., Szalapko J.

Archives of Materials Science and Engineering

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2013

|

Vol. 59, nr 2

69--75

EN

Purpose: The aim of this research is to determine the construction parameters and the working parameters of the rotors modeled with the aid of the computer simulations. This research is conducted in the context of its application in different systems for sewage rectification. Design/methodology/approach: Modeling and process analysis of the fluid flow under the working rotor conditions simulated with the SolidWorks 2010 - Flow Simulation Module. Findings: The results presented here refer to the testing conducted for the systems of fluid flow under the real and virtual conditions. Research limitations/implications: The studying of the fluid flow process under working rotor conditions permitted to obtain credible results for the applied FEM scheme. Practical implications: FEM can be used as an effective tool for examination of the fluid flow phenomena for different working conditions of the flow systems. The latter holds provided pertinent tools for FEM analysis are invoked. Originality/value: Application of FEM for studying fluid flow processes on the example with rotors.

15

Problem of the moving boundary in continuous casting solved by the analytic-numerical method

Grzymkowski R., Pleszczyński M., Hetmaniok E.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 1

33--38

EN

Mathematical modeling of thermal processes combined with the reversible phase transitions of type: solid phase – liquid phase leads to formulation of the parabolic or elliptic moving boundary problem. Solution of such defined problem requires, most often, to use some sophisticated numerical techniques and far advanced mathematical tools. The paper presents an analytic-numerical method, especially attractive from the engineer’s point of view, applied for finding the approximate solutions of the selected class of problems which can be reduced to the one-phase solidification problem of a plate with the unknown a priori, varying in time boundary of the region in which the solution is sought. Proposed method is based on the known formalism of initial expansion of a sought function, describing the field of temperature, into the power series, some coefficients of which are determined with the aid of boundary conditions, and on the approximation of a function defining the freezing front location with the broken line, parameters of which are determined numerically. The method represents a combination of the analytical and numerical techniques and seems to be an effective and relatively easy in using tool for solving problems of considered kind.

16

Deformation process of the material of mine powered roof supports in low-cycle fatigue conditions

Okrajni J., Plaza M., Jaszczuk M.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 50, nr 2

59--65

EN

Purpose The main purpose of the work is the description of the low-cycle fatigue process of mine powered roof supports working under mechanical high loading. The work focuses on the chosen component strain-stress characteristics. The issue of modelling the stress-strain behaviour of powered roof supports components during low-cycle fatigue has been discussed. Design/methodology/approach: The FEM modelling and Neuber’s method have been used to describe the local stress-strain behaviour of the chosen component. Findings: In the examined devices, variable stress and strain values were calculated for a chosen characteristic load cycle. Diagrams in the form of a hysteresis loop determined using Neuber’s hypothesis and FEM were compared. The values of the range of equivalent strain determined for multiaxial stress states using the finite element method proved to be close to those estimated via Neuber’s method. Research limitations/implications: The presented analysis is the part of the complex investigation method which main purpose is increasing the accuracy of the low-cycle fatigue process description. In such situation the investigations curried out in the work give the model approach and data for the comparison the real behaviour with the predictions. However the work is focused only on the chosen component and chosen characteristics of loading. Practical implications: The method of stress-strain behaviour analysis used in the paper could be useful in the practical cases when the real components mechanical behaviour would be analysed and their fatigue life would be assessed. Originality/value: The main value of this paper is the own method of the mechanical behaviour analysis of the powered roof support component. This method includes FEM modelling and Neuber’s method of the stress-strain characteristics assessment. The material stress-strain behaviour has been treated as the local phenomenon that could be modelled.

17

Application of feature based method in constructing innovative sheathing of railway wagons

Baier A., Majzner M.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 52, nr 2

91--98

EN

Purpose: The aim of this work is to present the use of composite materials in the construction of freight cars. Particular attention was paid to the use of these materials in the construction of a freight wagon door. It is dangerous when mechanical damage is made to wall panels of a wagon during transport. Improperly distributed transported material can exceed the allowable stress level and thereby damage the lining of the wagon. One possible solution to this problem is replacing steel plates with composite panels which have better mechanical properties and do not cause an increase of the nominal weight of a freight wagon. Design/methodology/approach: Experimental studies included: develop a research methodology of experimental tests of deformation of the wall door of a freight wagon. using strain gauge, placing strain gauges at key points, performed single-layer and double layer laminate panels with steel plates. Findings: Composite materials made of 5 mm steel plate and a multilayer laminated panels can be used in the construction of freight cars. Research limitations/implications: An expanded scope of the studies would include an analysis and synthesis of composite panels of various thicknesses, depending on the degree of damage to the hull of a freight wagon. Practical implications: Composite panels can be applied in the repair and construction of freight wagon shells. The obtained result shows the possibility of reducing the weight of the whole railway carriage and the price of a wagon repair, eliminating the need to completely remove the shell. Originality/value: Innovative use of composite panels in the repair and construction of structural elements of freight wagons, is new to the Polish scale. Initially DB Schenker Poland, is development of interest in further research and implementation of new technology.

18

Unsteady state heat flow in the exhaust valve in turbocharged Diesel engine covered by the layer of the carbon deposit

Hornik A., Jędrusik J., Wilk K.

Archives of Materials Science and Engineering

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2012

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Vol. 54, nr 2

68-77

EN

Purpose: The determination of the temperature distribution, temperature gradients and thermal stresses in the exhaust valve with using the layer of the carbon deposit in initial phase of the work of turbocharged Diesel engine. Design/methodology/approach: The results of calculations of the temperature distribution, temperature gradients and thermal stresses in the exhaust valve of turbocharged Diesel engine with using the layer of the carbon deposit on the different surfaces of the valve were received by means of the two – zone combustion model and the finite element method. Findings: The computations presented the possibility of use of the geometrical models of the layer of carbon deposit on the different surfaces of the exhaust valve and heat transfer on individual surfaces of the exhaust valve used by the variable values of the boundary conditions and temperature of working medium in initial time of the working engine. Research limitations/implications: The modelling of thermal loads were carried out by analysing the temperature distribution, temperature gradients and thermal stresses in the exhaust valve in initial phase of the work of turbocharged Diesel engine. Originality/value: The layer of the carbon deposit was used for modelling of thermal loads in the exhaust valve as the geometric model with the use of material properties. The results obtained allow to analyse distribution of temperature, temperature gradients and thermal stresses in the exhaust valve.

19

Numerical modeling of melting process of thin metal films subjected to the short laser pulse

Majchrzak E., Dziatkiewicz J.

Archives of Foundry Engineering

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2012

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Vol. 12, iss. 4

105-108

EN

Thin metal film subjected to a short-pulse laser heating is considered. The parabolic two-temperature model describing the temporal and spatial evolution of the lattice and electrons temperatures is discussed and the melting process of thin layer is taken into account. At the stage of numerical computations the finite difference method is used. In the final part of the paper the examples of computations are shown.

20

The influence of the engine speed on the temperature distribution in the piston of the turbocharged diesel engine

Hornik A.

Transport Problems

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2011

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T. 6, z. 3

93-98

EN

This article presented the numeric computations of non-stationary heat flow in the form of distribution of temperature fields on characteristic surfaces of the piston for two different rotational speeds for the same engine load during 60 seconds during in which the engine worked. The object of research was a turbocharged Diesel engine with a direct fuel injection to the combustion chamber and the engine cubic capacity that is 2390 [cm3] and power rating, which is 85 [kW]. The numeric computations were carried out by the use of the finite element method (FEM) with the help of COSMOS/M software and the use of the two – zone combustion model.

PL

W pracy przedstawiono obliczenia numeryczne niestacjonarnego przepływu ciepła w postaci rozkładu pól temperatury na charakterystycznych powierzchnia tłoka dla dwóch prędkości obrotowych silnika przy porównywalnym współczynniku nadmiaru powietrza w czasie 60 sekundowej jego pracy. Przedmiotem badań był doładowany silnik wysokoprężny z wtryskiem bezpośrednim o pojemności 2390 [cm3] i mocy znamionowej 85 [kW]. Obliczenia numeryczne zostały przeprowadzone przy zastosowaniu metody elementów skończonych (MES) za pomocą programu COSMOS/M oraz przy wykorzystaniu dwustrefowego modelu procesu spalania.