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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

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.

3

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.

4

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.

5

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.

6

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.

7

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.

8

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.

9

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.

10

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

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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.

11

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.

12

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.

13

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.

14

Theoretical and experimental aspects of the bimetallic reinforcement bars steel - steel resistant to corrosion rolling process

Sawicki S., Dyja H., Mróz S., Szota P.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 1

371--378

EN

Purpose: Bimetallic bars which possess higher corrosion resistance and mechanical properties, it is the new kind of bimetallic bars, which are better than standard bars. The bimetallic bars are more often applied in concrete construction. Design/methodology/approach: The simulations of the bar rolling were carried out using the Forge2007® commercial program. Findings: The use of non-corrosive steel on plating layer assures receipt on a high durability and esthetics bimetallic bars. Practical implications: Bimetallic bars are chiefly used in the building industry at production of concrete constructions, and as working elements in bridge building in aggressive environment. Originality/value: Production of bimetallic bars is very difficult. One from many problems during production bimetallic bars is assurance good strength of bimetallic layer bond.

15

Simulation of the microhardness and internal stresses measurement of PVD coatings by use of FEM

Śliwa A., Dobrzański L. A., Kwaśny W., Staszuk M.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

|

Vol. 43, nr 2

684--691

EN

Purpose: The goal of this work is to determine microhardness of coats and stresses obtained in PVD process with the use of finite elements method and comparative analysis with results obtained by laboratory investigations. Design/methodology/approach: Article introduce the usage of finite elements method for simulation of microhardness and stresses measurement process in TiN and TiC coats obtained in magnetron PVD process on high-speed steel ASP 30. Simulation of indenters depression in investigated coat permitted on disclosure of deformation of the layer PVD and allows to create the maps of stresses. Findings: Basing tensions obtained as a result of indenter depression in investigated surfaces we obtained the maps of stresses, deformations analyzed of coats, and then we calculated the microhardness. Research limitations/implications: On the basis of tensions in investigated coat obtained in result of computer simulation effected in ANSYS software environment was possible to compute the microhardness of the coating, and the results was compared with the microhardness data of coats received by physical examination with use of the Vickers method. Originality/value: From results of the simulation based on the finite element method is possible to compute the mechanical properties of coatings obtained in PVD process.

16

FEM applications to the analysis of passive solar wall elements

Lenik K., Wójcicka-Migasiuk D.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

|

Vol. 43, nr 1

333--340

EN

Purpose: The evaluation of heat propagation effectiveness through passive solar modules of different construction in relation to selected process conditions by means of computer simulation. Design/methodology/approach: The analysis of heat transfer through laminar structures in transient states by means of FEM and its verification on small scale models during laboratory tests. Findings: The paper presents the application of FEM and its methodology of computations for the established conditions on both sides of laminar structures specific for solar passive-thermal modules. The results are compared to small scale experimental results. The verification of the analysis leads from particular conclusions concerning the procedure of simulations towards general comments on the application of real modules. Research limitations/implications: The research has been carried out by means of software suitable for field analysis with some limitations to 3D which have been specified but their influence on usefulness of results is only minor. The verification on a small scale model is necessary and reliable in terms of the research consistence. Practical implications: Finite Element Method exploited in the applied methodology of investigation can be successfully used as a tool to examine energy transfer at considerations on different laminar structures. The subject of the research, i.e. solar passive modules confirmed their usefulness for energy demand reduction but with some identified restrictions. Originality/value: The use of small scale solar modules to verify FEM analysis and the combination of both analyses to determine the applicability of modules in real conditions of solar energy conversion in different building objects.

17

Application of the homotopy perturbation method for calculation of the temperature distribution in the cast-mould heterogeneous domain

Grzymkowski R., Hetmaniok E., Słota D.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 1

299--309

EN

Purpose of this paper: In this paper an application of the new method for solving the heat conduction equation in the heterogeneous cast-mould system, with an assumption of the ideal contact at the cast-mould contact point, is introduced. An example illustrating the discussed approach and confirming its usefulness for solving problems of that kind is also presented in the paper. Design/methodology/approach: For solving the discussed problem the homotopy perturbation method is used, which consists in determining the series convergent to the exact solution or enabling to built the approximate solution of the problem. Findings: The paper shows that the homotopy perturbation method, effective in solving many technical problems, is successful also for examining the considered problem. Research limitations/implications: Solution of the problem is provided with the assumption of an ideal contact between the cast and the mould. In further, research of the discussed method shall be employed to solve problems involving the presence of thermal resistance at the cast-mould contact Practical implications: The method allows to determine the solution in form of the continuous function, which is significant for the analysis of the cast cooling in the mould, in order to avoid the defects formation in the cast. Originality/value: Application of the new method for solving the considered problem.

18

Application of the computer tomography in examination of the internal structure of materials by considering the specific conditions of the problem

Grzymkowski R., Hetmaniok E., Pleszczyński M., Zielonka A.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 1

288--298

EN

Purpose of this paper: In this paper we present a summary of the results reached in the field of computer tomography applied in some special case – for the problem of incomplete projection data. This particular problem arises in the technical issues in which, for some reasons (like for example size of the examined object, its localization or its accessibility), it is impossible to apply the standard algorithms of computer tomography. Design/methodology/approach: In the paper we discuss the standard algebraic algorithms of computer tomography and, additionally, the new algebraic algorithms (parallel and chaotic), designed by the authors, suitable not only for the case of incomplete projection data but also useful in the standard approach. Findings: The above mentioned algorithms are tested in solving the problems of reconstruction the discrete objects of high-contrast. Moreover, convergence, stability and utility of the algorithms are proved experimentally. Research limitations/implications: Algorithms, created by the authors, are designed for the multiprocessor computers which allow to execute the calculations simultaneously. However, the results compiled in the paper were elaborated by using the one-processor computer. Calculations in which the parallel computing structure will be used are planned for the nearest future.Practical implications: Possibilities of the effective applications of the discussed algorithms in different practical technical problems are showed in the paper. Research, done till now, indicate the chances of applying the proposed algorithms in certain technical problem in which the incomplete projection data appear (like, for example, in searching for the elements in material which cause decreasing of its strength or in looking for the compressed gas reservoirs in the coal bed, which can be dangerous for the people’s life and health). Originality/value: The paper presents the reconstruction algorithms (block and chaotic-bloc), designed by the authors, which appear to be more effective than the standard algebraic algorithms adapted for solving problems with the incomplete projection data.

19

Analysis of stress state in DMTA and photoelasticity examinations

Gnatowski A., Palutkiewicz P., Lubczyńska K.

Archives of Materials Science and Engineering

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2010

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Vol. 46, nr 1

39-46

EN

Purpose: Determination of stresses at the change of Young modulus values in temperature function for polystyrene samples, by DMTA and photoelasticity method, was the aim of work. The numerical simulations of stress, strain and displacement in PS samples was presented. The numerical simulations of injection moulding process (using Moldflow Plastic Insight 5.0 software), include effects after injection process were conducted. Design/methodology/approach: Investigations were carried out for samples subjected to the one-axial bending. The computer simulations of changes of the stress and strain distribution within the range of elastic strains phase were done. The change in the value of the dynamic Young modulus and the mechanical loss tangent in function of temperature and oscillation frequency by the DMTA method was determined. To verify numerical simulation the photoelasticity research was done. Findings: Examinations made possible the determination of dynamic mechanical properties of polystyrene and changes in the stress distribution during the dynamic loading of the sample in function of temperature. Higher values of the Young modulus were observed within the range of elasticity. The stress increased with the increase in Young modulus, at the strain generated from push rot oscillation Research limitations/implications: The injection moulded part have large internal stresses, with higher value than stresses made from oscillation pushrot. The accuracy of used approximate method for computer simulations was not sufficient to indicate the Bielajew point. Practical implications: Investigated polymer is characterized by viscoelastic properties, so all indicators of the physical and chemical properties depend on not only the time but and also the temperature. Originality/value: To characterize properties of investigated polymer and to estimate the polymer usage in particular conditions, dependences of the storage module and the mechanical losses tangent was determined in function of temperature at the one-axial bending. The impact of internal stresses in the sample was investigate.

20

Numerical analysis of short-pulse laser interactions with thin metal film

Majchrzak E., Poteralska J.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 4

123--128

EN

Thin metal film subjected to a short-pulse laser heating is considered. The hyperbolic two-temperature model describing the temporal and spatial evolution of the lattice and electrons temperatures is discussed. 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.