bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of heat transfer coefficients for simulation of the heat exchange between oil and the internal cavity faces of the isolated piston at variable gravity conditions
Authors: Bilohub A , Van Duong N , Sirenko F , Savchuk V , Bilousov I , Symonenko R , Zajačko I 
Published: April 2020

Abstract
The paper deals with the problems related to the development of a new piston design for replacement during repair in 2-stroke D-100 engines for locomotives. The paper addresses the design, the mass of which is 35 % less than the mass of the prototype. The results of thermal calculation, which served the initial data for the temperature and heat transfer coefficients evaluation over the heat-receiving surface of the combustion chamber of the piston, coincide with the experiment of prof. G. Rosenblit. The integral boundary conditions were refined by calculating five successive engine cycles, αP
= 1830 W m–2 K–1 and Teq p
= 970 K were selected for further research. Next, heat transfer from the piston internal cavity to the oil, which is supplied through a nozzle in the small head of the connecting rod, was studied. The study included a 3D simulation of the cooling oil movement from the nozzle to the inner surface, both in the stationary mode (Earth’s gravity field) and taking into account the variable acceleration of the piston at the design mode. In this case, the location of the holes in the nozzle, the flow parameters and the properties of the oil were simulated. The study showed that taking piston acceleration into account leads to a slight difference in heat transfer coefficient in the center of the piston (830–800 W m–2 K–1) and rather large at the periphery (600 … 520 W m–2 K–1 taking into account the acceleration of the piston against 460 … 420 W m–2 K–1). It is shown that the nozzle with 4 holes and the angle of inclination of the side holes φ = 55° gives a more efficient cooling.
The fault tree stochastic analysis
Authors: Chovanec A , Breznická A , Mikuš P 
Published: April 2020

Abstract
This article presents a solution of the fault tree quantitative analysis with application of knowledge of probability distribution type into the failure and distribution parameters in case of non-renewed objects or objects being restored. It brings a look at fault tree solving based on statistical view using mathematical modeling. In this article present relations of FTA analysis for quantitative deterministic approach that is most commonly used.
Experimental and numerical tests of clinch connections strength
Authors: Dudziak M , Talaśka K , Wilczyński D 
Published: April 2020

Abstract
The work presents experimental investigations of clinch connections of structural wooden elements. The tests were carried out using the MTS Insight 50 kN laboratory testing machine. The influence of changing parameters such as the angle of sharpening γ staples, which values were successively 30° and 60°, and the mutual positioning of the staple legs, which was parallel, divergent and convergent, were investigated. The presented results gave information on which parameters, the connection strength is the highest. Experimental research was also supported by numerical studies in which the phenomenon of destruction of this type of connection was simulated. The built-in numerical model gives the opportunity to examine the connection strength for a larger number of cases of change in the value of the angle γ and the angle of mutual positioning of the staple legs.
Stress analysis of specimen with a reinforced thin layer
Authors: Handrik M , Vaško M , Majko J , Kopas P , Jakubovičová L , Halama R , Fusek M 
Published: April 2020

Abstract
The paper presents an analysis of the stress state in the tensile test sample. The test sample has a hardened surface layer with chemic heat treatment – cementation. The analysis was carried out for various thicknesses of the reinforced cemented layer. If the whole thickness of the material is not cemented, the fracture is near the grip section of the specimen. The analysis results explain the cause of this fracture.
Simulation of wood biomass combustion in hot water boiler
Authors: Klačková I , Zajačko I , Lenhard R , Gritsuk I , Wiecek D 
Published: April 2020

Abstract
Calculation methods based on finite volume methods (CFD method) have proven to be very useful in optimizing (efficiency, emission) heat sources for wood burning. Such heat sources also include gasification hot-water boilers for the combustion of dry wood. One of the important parts of the entire process of converting the primary energy contained in the fuel to the transfer of heat to the heat carrier is the gasification of the fuel in the feed chamber and the subsequent burning of wood gas. The paper presents CFD simulation of wood gasification process in the filling chamber and subsequent burning of wood gas on a model heat source. As a model heat source, was selected a hot-water boiler with lower fuel firing with a flue gas-water heat exchanger tubular heat exchanger. It is a gasification hot water boiler for the combustion of dry wood. The interior of the boiler consists of a filling chamber where the fuel is dried and fused. The wood gas then passes through the nozzle to the combustion chamber, where it burns with the aid of secondary air. The flue gases pass their heat in the heat exchanger through the walls of the pipes into the water.
3D technology implementation in medicine
Authors: Macko M , Szczepański Z , Mikołajewski D , Mikołajewska E , Furtak J 
Published: April 2020

Abstract
New modern additive technologies and reverse engineering are becoming available, especially in medical applications. The paper presents possible ways of using additive technologies in the scope of increasing the level of training of medical specialists in everyday clinical practice and in the selection of the appropriate scenario before real surgery. Descriptions of projects implemented with surgeons whose effect is to achieve aforementioned goals have been presented. The concepts are known as new solutions, but their further development may lead to the extension of the scope of application of these techniques in medicine, among others in relation to other disciplines.
CAE analysis and simulations of technological processes of selected high strength steels
Authors: Majerík J , Barényi I , Ladecký M , Krbaťa M 
Published: April 2020

Abstract
The article of authors deals with the design of the structural part of the bodywork in the CAE system CATIA using the CAE software solutions of the Autoform system, which are based on the finite element method. This design was subsequently implemented into the design of dies in order to achieve the most efficient and high-quality dies, which are increasingly required in industrial practice for lifetime and functionality. Three types of high-strength steels TRIP HCT780T, DP-HCT780X and CP-HCT780C with approximately the same tensile strength were selected for the experiments. Based on the input parameters, simulations were implemented and the results obtained from the simulations will be the basis for selecting the most optimal variant. The main measurable and evaluative factor was the outputs obtained from the FLD diagrams.
Evaluate of time delays influence on effectiveness of nonlinear saturation controller. Part I: Modelling
Authors: Mitura A , Rusinek R 
Published: April 2020

Abstract
In this paper a numerical model of a strongly nonlinear beam with attached vibration control system is presented. To reduce vibration a saturation controller is applied. Its input and output are time delayed signals. To estimate an influence of time delays on the control effectiveness, two indicators are proposed. The first indicator is quantitative, while the second one – qualitative is based on value of the largest Lyapunov exponent. The numerical procedure for estimating this exponent is developed and tested.
Simplified approach for creep evaluation in superheaters
Authors: Naď M , Lošák P , Létal T , Pernica M 
Published: April 2020

Abstract
This paper is focused on the estimation of temperature distribution on superheater tube bundles for the consequent creep damage evaluation. The precision of estimated temperatures is very important because it significantly affects residual creep life. Conditions in the tube bundle can be simulated using CFD, however, a full 3D simulation would be computationally intensive and not fit for practical use. In order to mitigate this issue, the new approach considered in this paper uses a series of 2D CFD simulations in multiple sections using known inlet flow conditions. Those conditions have been investigated in previous work using 3D CFD simulation of flue gas flow starting in the combustion chamber and ending just before the superheater in the second pass. The paper also deals with possible temperature differences that may arise due to simplifications in the proposed approach. Lastly, the residual creep life is estimated using obtained temperature distribution on the tube bundle.
Construction proposal of shipping bulk container
Authors: Poklemba R , Zajac J , Goldyniak D , Olexa I , Dilýová M 
Published: April 2020

Abstract
The presented paper is focused on proposal of folding container that would minimize this problem and reduce transportation costs. Transportation has been an important part of everyday life in the past. Crates of various shapes and sizes were used to transport various goods, the main task of which was to protect the material from adverse atmospheric influences. As a result of technology development, people have tried to simplify the way they transport different materials or products. Containerisation has arisen for the need to transport more goods over longer distances, even between continents. The work also contains descriptions of individual graphic systems through which it is possible to implement the container proposal before its production. In the last part there is a comparison of the classic folding container in terms of its transport and description of its construction.
Numerical analysis of thin-walled component structure
Authors: Pytliński R , Wojtkowiak D , Talaśka K 
Published: April 2020

Abstract
Thin-walled components are commonly employed in the broadly understood engineering applications. From building construction, to machine building and acoustic system components. The design calculations for this type of structures are complex and time consuming. The paper presents an MES analysis of a thin-walled component in the example of a speaker membrane. The aim of the analysis is to determine the deformation characteristics of the membrane as a function of its deflection by the voice coil. The examined component is constructed from two materials, which was reflected in the model. The paper presents the methodology of building the MES model, modeling of selected materials forming the structural composition of the membrane as well as interpretation of results. The contents provided in the paper may be of use for the purpose of determining the correct construction of these components in order to improve their working efficiency.
Thermal-stress analysis of vulcanization molds to determine the dilatation gap between aluminum segments
Authors: Vaško M , Sága M , Ságová Z , Handrik M , Kopas P , Jakubovičová L , Muraviev V V , Muravieva O V 
Published: April 2020

Abstract
The aim of the paper is to present a methodology for calculating the gap between segments of a tire vulcanizing mold in order to prevent rubber from flowing out of the mold when heated to 165 °C. The analysis will be performed for four types of molds for the manufacturing of tires for passenger cars. Segments for containers K1 to K4 with their minimum and maximum dimensions were selected for analysis. Deformation values in radial and tangential directions for all four segment types were evaluated by computational analysis. The finite element method (FEM) was used for the analysis using the ANSYS computational program. The calculation was made on the finite-element models of the aluminum segment, its carrier and the tightening ring. The boundary conditions were selected for each load case to really characterize the physical phenomenon.
Analysis of the guiding column and sleeve cooperation in the linear slide bearing of the punching die head-punch block
Authors: Wojtkowiak D , Talaśka K , Berdychowski M 
Published: April 2020

Abstract
A proper cooperation of the guiding column and sleeve in the linear slide bearings of the punching die head-punch block is very important in the context of alignment between the punch and the die. Multiple factors like the shaft and sleeve tolerances, contact surface roughness or the type of loading applied to the bearing may have an effect on the movement of the mechanism. In the paper authors focus on the influence of the linear slide bearings distribution on the punching die plate on the stress distribution on the column and the sleeve as well as on the deflection of the head-punch block. It is especially important for the punching dies with one-sided guiding that enables moving it toward the center of the material to perform a designed perforation pattern. Considering the machines for polymer composite belt perforation, the deflection of the head-punch block has to reach its minimum since very small punch-die clearances (below 1 % of the hole diameter) are used. The presented FEM analyses provide a lot of useful information and enable designing effective constructions of the punching die. Additionally, the effect of the return spring system was also modelled.
Application of the Mohr-Coulomb model for simulating the biomass compaction process
Authors: Berdychowski M , Talaśka K , Malujda I , Kukla M 
Published: April 2020

Abstract
Presently, there are many different available material models. Some are used for modeling loose materials such as soil and sand. Such models could be usable for modeling the behavior of fragmented biomaterials e.g. sawdust. The subject of the present article is the M-C model, one of the models for describing the characteristics of plasticity in a material. The article presents the method of determining the material constants used in this model, including the cohesion coefficient and angle of internal friction. The results and types of experimental examinations necessary for the purpose of the implemented task are also presented herein. The study was carried out for the oak and pine sawdust mix.
The Cam-Clay model in the application of technological process modeling
Authors: Berdychowski M , Wilczyński D , Talaśka K , Wojtkowiak D 
Published: April 2020

Abstract
The article presents the preliminary results of numerical simulations of the densification process of shredded waste wood. The purpose of the simulation was to evaluate the possibility of using the Cam-Clay model in the field of modeling plastic deformation of shredded biomaterials. The results of simulation was compared with experimental research. The study employed a special stamp-cylinder assembly adapted for mounting on a strength machine. Sawdust was compacted with sufficient force to obtain the desired compressive stress in the sample cross-section. In the experiment, the mixture of oak and pine was used in proportions of 50 % of each material.
Modelling of wear out of timing belt’s pulley
Authors: Domek G , Kołodziej A , Wilczyński M 
Published: April 2020

Abstract
The paper deals with the problem of volumetric wear of timing pulleys. The authors analyze the course of this phenomenon depending on the properties of the belt-pulley friction pair. Timing belts are made of various materials, including additional coating layers, similarly to pulleys. The gear operation problem consists in modelling the pulley life for specific gear materials. The authors made also an attempt to investigate the rate of this phenomenon and its impact on the kinematic efficiency of the transmission gear with timing belts.
Static tests the stiffness of car tires
Authors: Dudziak M , Lewandowski A , Waluś K J 
Published: April 2020

Abstract
Safe driving requires from the driver a number of manual actions related to the existing traffic situation. The vehicle, reacting to the imposed extortions, is subjected to three-axle loads, which are transferred by friction-shaped coupling of the tire with the surface. The generated forces affect the tread and the side of the tire, the suspension of the vehicle and the steering. The article presents the results of bench tests of two types of tires: tires with special tread (coloured) made to order and popular tires available in retail sales. The tests were carried out under static conditions. The tests were carried out in cooperation with the Stomil Tire Research and Development Center in Poznan on the position enabling acquisition and archiving of the values of forces in the function of displacement (deformation of the tire). The obtained results made it possible to determine the directional stiffness of the radial, peripheral, lateral and torsional tires. It allowed to build the stiffness characteristics and compare the response to the forced testing tires. The results obtained form the basis for analysing the scope of vehicle traffic safety, and can also be used as input data in simulation tests.
Imaging and computer analysis in the shape error measurements and in the cylindrical objects stereometry
Authors: Zaborski A , Winczek J 
Published: April 2020

Abstract
In the work, the application of the imaging method and computer analysis of the results of cylindrical surface measurements are presented. Experimental studies focused on determining the measurement of shape, surface roughness and surface stereometry. The measurements were taken on Taylor-Hobson’s Talyrond 365 computerized stand. The selected parameters describing the profiles of cylindricity were analyzed in detail, which allowed to reflect the three-dimensional shape of the analyzed cylindrical surface and determine the shape errors. The results of the roughness measurements are shown in the form of a stereometric images developed cylinder surface. Computer analysis of the results allowed to isolate waviness and surface roughness. The results of the computer analysis were verified by stereometric measurements on the profilograph. Analysis of the achieved results confirmed shown satisfactory compatibility.
Dynamic modelling of elastic plates reinforced by strong fibres
Authors: Milosavljevic D I , Sapietova A , Zmindak M , Dekys V , Novak P 
Published: April 2020

Abstract
Here are considered composite materials reinforced which strong fibres, which have an important property that they are anisotropic, and in many cases this anisotropy may be very strong, in the sense that mechanical properties are strongly dependent on direction. Such materials are highly resistant to deformation by extension in the fibre direction compared to other deformation modes. Thus material has been modelled as a transversely isotropic for which the extensional modulus in the fibre direction is much greater than that in a direction perpendicular to the fibres. Material is modelled as coordinate free and such model is employed for examination of waves propagating in an infinite plate reinforced by strong fibres. Wave propagation in layer reinforced by one family of fibres with wave direction parallel with stress free boundaries, but otherwise with angle arbitrary to fibre direction, are examined here. The dispersion relations, in specific carbon fibres - epoxy resin composites, are examined. Expressions are also obtained for the variation of displacements and stresses through the thickness of the plate.
Using of wood ash as the alternative filler for preparation of rubber mixtures
Authors: Feriancová A , Pajtášová M , Moricová K , Pecušová B 
Published: April 2020

Abstract
Processing and material recovery of waste is an important aspect of environmental policy. Ash is waste in terms of legislation, but it is also a material that can be reused. Various works propose that biofuel ash could be used as inorganic fertilizer. The object of this work is based on using of wood ash (WA) from biomass and its modified form as the alternative filler in rubber mixtures. The WA samples with particle size of 25 and 40 µm were modified by silanization and properties of ash samples were characterized by elemental analysis (EDX), Scanning Electron Microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). Model rubber blends were prepared by using modified wood ash as a partial replacement of conventional filler. Furthermore, the influence of the addition of ash on the cure characteristics (minimum torque – ML
, maximum torque – MH
, optimal cure time – t90
, scorch time ts2
), mechanical properties (tensile strength at break – TSb
, elongation at break – Eb
and hardness) and physical properties (cross-link density) in sulfur-cured SBR composites were investigated. Dispersion of the WA filler and its incorporation into vulcanizates were based on observation of the fracture surfaces of vulcanizates by SEM. The results confirmed that the wood ash did not significantly affects the mechanical properties of the vulcanizates and can be used as a partial replacement of carbon black in SBR vulcanizates.
Research and application of PLA fibres
Authors: Kleščík M , Bizubová B , Zatroch T , Balogová A , Pedraza L A R , Skalková P , Krmelová V , Krmela J , Muks E , der Scheuren L V 
Published: April 2020

Abstract
This work is focused on characterization of spinning process of PLA fibres. PLA polymer with high melting point was modified by two hydrolytic additives in amounts (0 and 1 wt. %). Fully drawn (FDY) PLA fibres were prepared by melt spinning technique in the company Chemosvit Fibrochem a. s. (Svit, Slovakia). Preparation of PLA fibres was done by two different processes of continuous and discontinuous type. Different drawing ratios, take-up speeds and spin finishes for optimal fibre properties were used. Physical and mechanical properties of prepared FDY fibres, such as elongation and tenacity were measured. Prepared PLA fibres with different hydrolytic additives were process able in manufacturing process and this material could be used for various textile and composite applications.
Study of structural changes in thermoplastics using dynamic mechanical analysis
Authors: Kohutiar M , Janík R , Pajtášová M , Ondrušová D , Labaj I , Zvoláneková Mezencevová V 
Published: April 2020

Abstract
Diffuse coplanar surface barrier discharge (DCSBD) is an innovative plasma source that finds application in industrial practice and also in the surface treatment of various types of materials. The presented paper deals with the investigation of structural changes in selected thermoplastic materials that have occurred after their treatment with plasma discharge. The structural changes were investigated by using dynamic mechanical analysis, where the changes between the unmodified material samples and the thermoplastic material samples exposed to the plasma discharge, were compared, based on the obtained data of the storage modulus, the loss modulus and the loss tangent. For the experiment, thermoplastic materials were chosen, which are widely represented in the production of packaging materials, namely polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET).