Communications - Scientific Letters of the University of Zilina - Latest articles

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Multi-Leg Shear Reinforcement of Gfrp and Steel Lwrc Edge Column-Slab Connections: A Comparison StudyCivil Engineering in Transport

Mustafa F. Saeed, Ibrahim S. I. Harba

Communications - Scientific Letters of the University of Zilina 2024, 26(4):D92-D108 | DOI: 10.26552/com.C.2024.048  

The behaviour of lightweight concrete (LWC) edge column-slab connections reinforced with two types of flexural reinforcement glass fiber-reinforced polymer (GFRP) and steel bars with different ratios of shear reinforcement are investigated experimentally and analytically using ABAQUS software. The experimental protocol covered evaluation of eight slabs and edge columns measuring subjected to static loading. Slabs are evaluated as supported, free-standing at one edge, and the column connection is included. The slabs are divided into two groupings, with four slabs in each group. The first group was reinforced with steel flexural, while the second group...

Relationship between the Transport Performance and Financial Coverage in Urban Public Transport in the Czech RepublicOperation and Economics in Transport

Josef Kubík, Tomáš Urbánek

Communications - Scientific Letters of the University of Zilina 2024, 26(4):A65-A74 | DOI: 10.26552/com.C.2024.042  

The research presented aimed to compare the transportation performance, as measured by vehicle kilometers, to the operating costs incurred by thirteen transport companies in the Czech Republic from 2010 to 2019. This period was chosen to ensure that our research is not affected by the Covid-19 pandemic. The financial coverage of operating costs includes revenues from fares and compensations from city budgets. We utilized data from the annual reports of The Association of Transport Companies of the Czech Republic. Based on the obtained data, we confirmed a positive relationship between the city's population, the extent of transportation performance,...

The Effectiveness of Public Intervention in the Regional and Urban Mobility Based on the Examples of Poland and SlovakiaOperation and Economics in Transport

Jozef Gnap, Grzegorz Dydkowski, Anna Urbanek

Communications - Scientific Letters of the University of Zilina 2024, 26(4):A75-A88 | DOI: 10.26552/com.C.2024.052  

Ensuring the sustainable development of urban and regional public transport systems is one of the major challenges faced by public authorities. This article examines changes over more than two decades in the two key synthetic measures for balancing transport: urban and regional public transport and individual motorization in two neighbouring EU countries, Poland, and Slovakia. The findings reveal the low effectiveness of transport sustainability policies, particularly in Poland, as evidenced by a decline in public transport usage and a significant increase in the number of private cars. Comparing the two countries Slovakia's policies proved more effective,...

Investigating the Characteristics of Modified Bitumen with Polyphosphoric Acid Polymers and Recycled RubberCivil Engineering in Transport

Sajad Chavoshi Najfabadi, Mohammad Mehdi Khabiri, Hamed Khani Sanij

Communications - Scientific Letters of the University of Zilina 2024, 26(4):D109-D121 | DOI: 10.26552/com.C.2024.050  

The impact of polyphosphoric acid (PPA) polymers and crumb rubber (CR) on bitumen's properties to enhance its performance was examined in this study. Laboratory samples were created with varying percentages of PPA (0.5 % to 2 %) and CR (6 % to 18 %) and subjected to extensive testing. Findings indicated that the combination of PPA and CR led to notable improvements in bitumen performance, including increased viscosity, softening point, elasticity, and recovery rates at elevated temperatures. Specifically, samples with 18 % CR and 1.0 % or 2.0 % PPA demonstrated exceptional rheological properties and strength. The optimal combination (18% CR and 1.0%...

Technological Properties of Cylinder Liners of Automotive Internal Combustion Engines Restored by Centrifugal Induction SinteringMechanical Engineering in Transport

Khasan Ilyamov, Zhandos Zhumagulov, Erbol Sarkynov, Shamil Abdreshov, Gabit Bakyt, Yerzhigit Saparbayev

Communications - Scientific Letters of the University of Zilina 2024, 26(4):B260-B269 | DOI: 10.26552/com.C.2024.051  

Cylinder liners of an automotive internal combustion engine are subject to significant losses during operation. Severe operating conditions of cylinder liners lead to the appearance of various defects that must be eliminated to ensure the performance of the internal combustion engine. Currently, several methods have been developed for restoring and strengthening the inner surface of cylinder liners of automobile and tractor engines. Analyzing the considered methods for strengthening and restoring cylinder liners, their advantages and disadvantages from the point of view of increasing their durability, it can be assumed that the high-quality restoration...

Evolution of the Product and Process Requirements during the Project LifetimeMechanical Engineering in Transport

Łukasz Rudolf, Marek Roszak, Lenka Kuchariková

Communications - Scientific Letters of the University of Zilina 2024, 26(4):B252-B259 | DOI: 10.26552/com.C.2024.049  

The automotive industry, known for its dynamism and innovation, relies on effectiveness of product and process requirements management. Effective collaboration with OEM (Original Equipment Manufacturers) is essential for success. The article analyses how product and process requirements evolve during different project phases, following the APQP (Advanced Product Quality Planning) approach, depending on OEM type. The study focuses on Tier 1 organizations, direct suppliers to the automotive industry, and their diverse approaches to product development. It underscores the need for Tier 1 organizations to maintain flexibility in their operations and to...

Research and Development of a Special Air Cushion Conveyor Design for the Transportation of Bulk CargoesMechanical Engineering in Transport

Gulshat Sarsenova, Kuralai Joldassova, Baktybek Sultanaliev

Communications - Scientific Letters of the University of Zilina 2024, 26(4):B244-B251 | DOI: 10.26552/com.C.2024.045  

The scientific task of the nozzle scheme uses for formation of an air cushion by using the energy of a jet of air supplied under pressure, simultaneously to form an air cushion, as well as to create the driving force of a load-bearing web, was formulated and the main idea of the work was defined. The optimal option to significantly increase the productivity and length of special types of conveyors is to use the energy of a jet of air supplied under pressure simultaneously as an air cushion and as the driving force of the load-carrying body, which makes it possible to sharply reduce the coefficient of resistance to movement of the load-carrying body...

Substantiation of Parameters of Cargo Movement by Car Rope SystemsMechanical Engineering in Transport

Roman Rohatynskiy, Ivan Gevko, Oleg Lyashuk, Victor Aulin, Oleg Tson, Yuriy Nikerui, Andrii Horkunenko, Leonid Serilko, Bogdan Gevko, Olga Mosiy

Communications - Scientific Letters of the University of Zilina 2024, 26(4):B225-B236 | DOI: 10.26552/com.C.2024.041  

The automobile cable systems for loading and unloading operations between the vehicle-support and vehicle-vehicle points are presented in this paper. The scheme of the automobile mobile cable system is based on a two-cable cableway. Based on this scheme, the parameters of the movement of goods by automobile cable systems are substantiated at variable parameters: mass m artificial loads together with the mass of the frame structure: 35 ≤ m ≤ 95 (kg); the angle of inclination α pairs of parallel ropes to the horizon: 10 ≤ α ≤ 15 (°); tension force ropes 2400 ≤ T_D ≤ 5000 (N)....

Evaluation of Pedestrians' Gaze Behavior When Crossing the Road Using Eye-Tracking Technology: Implications for Autonomous Vehicle Led Communication InterfaceCivil Engineering in Transport

Symbat Zhanguzhinova, Emese Mako

Communications - Scientific Letters of the University of Zilina 2024, 26(4):D62-D70 | DOI: 10.26552/com.C.2024.044  

Since autonomous vehicles (AV) are in the testing process, it is an open question of how pedestrians will communicate with self-driving cars. Nowadays, explicit communication pattern is the main way of pedestrian-driver interaction, however, AV may use implicit communication when making crossing decisions. This study aims to analyze pedestrians' gaze behavior when crossing the road using an eye camera and find the most applicable location for the LED interface on AVs. 10 pedestrian crossings in Gyor, Hungary were analyzed using the synchronized eye-tracking (ET) technology and regular video cameras for combined data processing. The data were analyzed...

Impact of AI Technologies on Operations of Small and Medium Transport BusinessesManagement Science and Informatics in Transport

Vojislava Nićin, Slobodan Nićin, Milovan Mirkov

Communications - Scientific Letters of the University of Zilina 2024, 26(3):E12-E24 | DOI: 10.26552/com.C.2024.038  

In this article, the authors present a study on artificial intelligence (AI) integration in transportation and storage SMEs, focusing on research questions, literature reviews, hypotheses, sample selection, and data analysis. They explored current AI support and perceptions and plans of SMEs in this sector. The authors addressed the lack of literature on AI use in transport SMEs and investigated factors, such as AI adoption, benefits perception, company size correlation, and investment willingness. Data was collected from 163 SMEs in Serbia and Slovakia, revealing challenges in participant identification due to low AI use. Declining AI adoption rates...

Study of the Strength of the Open Wagon Hatch Door with Rectangular Corrugations under Static LoadsMechanical Engineering in Transport

Juraj Gerlici, Alyona Lovska

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B216-B225 | DOI: 10.26552/com.C.2024.039  

Rail transport has been the leading sector of the whole transport network. In order to improve the efficiency of its functioning, it is important to develop measures that may help reduce the maintenance cost. To improve the open wagon hatch door strength, it is proposed to make it with rectangular corrugations. The results of calculations show that, taking into account the proposed solution, the weight of the improved hatch door is almost 10% lower than the weight of a typical one.

Transport Efficiency Strategies in Assembly Workplace: A Case StudyMechanical Engineering in Transport

Dariusz Plinta, Ľuboslav Dulina, Beáta Furmannová, Ján Zuzik

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B187-B198 | DOI: 10.26552/com.C.2024.035  

In this article, improvements in assembly workplace layouts in an industrial context are investigated to enhance productivity and efficiency. The installation of the Cleaner M300 device is focused on, existing layout challenges are identified, and targeted improvements are proposed. Data collection, analysis, and real-world experimentation are employed to evaluate current workplace conditions and potential enhancements, including material flow dynamics and transport cart utilization. Proposed solutions are aimed at streamlining assembly processes, minimizing material transportation time, and boosting operational efficiency. The effectiveness of these...

Exemplary Determination of the Adhesion Ellipses Based on Simulation of an Accelerating Motor VehicleMechanical Engineering in Transport

Jarosław Zalewski

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B175-B186 | DOI: 10.26552/com.C.2024.032  

In the paper, some selected results concerning the ellipses of adhesion for various conditions of motion of a vehicle model, have been presented. The analysis, regarding the phenomena between the road and the wheels of the given motor vehicle's model, was previously carried out in the earlier paper by the author. However, they proved useful for the second part of research based on determination of the ellipses of adhesion. This can enable answering the question whether the road conditions may affect the maximum longitudinal and lateral forces combining such ellipses in the contact plane between the road and the wheels. The analysis has been presented...

Assessment of the Quality Indicators of the Carriage Movement by Directly Measuring the Forces of Interaction between the Wheels and RailsMechanical Engineering in Transport

Oleksij Fomin, Pavlo Prokopenko

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B155-B166 | DOI: 10.26552/com.C.2024.030  

This work describes the features and methods of measuring the forces of interaction between the wheel pairs and rails by measuring wheel deformations at control points. The work also contains recommendations for direct measurements of the forces of interaction between the wheels and rails to determine the actual margin of stability of wheel pairs from derailment. The result of the work is general requirements for the system of direct measurement of the strength of interaction of the high-speed rolling stock wheel pairs with rails and scientifically based recommendations for direct measurement of the interaction forces of wheels and rails. The problems...

The Power Analysis of Semiconductor Devices in Multi-Phase Traction Inverter Topologies Applicable in the Automotive IndustryElectrical Engineering in Transport

Jakub Šimčák, Michal Frivaldský, Patrik Resutík

Communications - Scientific Letters of the University of Zilina 2024, 26(3):C21-C38 | DOI: 10.26552/com.C.2024.034  

The article deals with the power analysis of semiconductor devices nowadays commonly used in perspective traction inverter topologies suitable for automotive industry applications.  The power analysis is devoted to topologies, which are the Voltage Source Inverter (VSI) topology and perspective three-level alternatives, which are the Neutral Point Clamped (NPC) and T-type Neutral Point Clamped (T-NPC) traction inverter topologies. The main part of the power analysis of the proposed topologies is done on multi-phase versions (specifically six-phase). Mentioned topologies are modelled through the use of the simulation environment PLECS, while the focus...

Structural Analysis of Designed Tubes under Axial Compression: Variations of Applied Temperature, Material Type, and Geometry DesignMechanical Engineering in Transport

Hensa Akbar Al Kautsar, Anandito Adam Pratama, Suryanto Suryanto, Aditya Rio Prabowo, Ristiyanto Adiputra, Heru Sukanto, Bambang Kusharjanta, Hermes Carvalho

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B199-B215 | DOI: 10.26552/com.C.2024.036  

The research presented in this article consisted of analysis of the ship structural accidents at low temperatures and the effect of carbon percentage in various classifications of carbon steel, compared to the high tensile strength steel materials. The objective of this research was to fill the knowledge gap by expanding the understanding of the influence of low temperature, material, and structure on the axial compression test of tubes. The simulations as idealization of the compression test were conducted with variations in temperature, material carbon percentage, and geometry shape, using Finite Element Analysis (FEA). The results showed that at...

Examining the Effect of Geometric Design Features on the Speed in Horizontal Curve on Mountain RoadCivil Engineering in Transport

Ehsan Ramezani-Khansari, Fereidoon Moghadas Nejad, Sina Moogehi

Communications - Scientific Letters of the University of Zilina 2024, 26(3):D52-D62 | DOI: 10.26552/com.C.2024.037  

In this study, the effect of five geometric design features, including radius, superelevation, longitudinal grade, lane and shoulder width, on the average speed in the horizontal curve on a two-lane undivided rural road was investigated. The standardized regression coefficients showed that the most important factor affecting the speed was the radius (10.47) followed by the longitudinal grade (4.46). Superelevation and lane width had little effect. Shoulder width had no significant effect. This would be due to the wide width of the lanes. It was found that the relationships between speed and radius, longitudinal grade, superelevation and lane...

The TE33A Series Diesel Locomotive Brake Equipment TestsMechanical Engineering in Transport

Seidulla Abdullayev

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B142-B154 | DOI: 10.26552/com.C.2024.029  

The purpose of the article was to present the results of braking equipment testing and determination of the adequacy of compressed air production of the braking system when the train is loaded. Experimental tests of the braking system of TE33A diesel locomotive in a goods train are performed. According to the initial data the main parameters of the braking system in the empty and loaded train were evaluated. As a result of tests, and according to the calculated data, the dependences of the volume of the main reservoirs, and the dependences of the required compressor capacity, on the number of axles have been obtained. It has been established that the...

Assessing the Impact of Three-Wheelers on Traffic Flow in India: A Case Study Using AnnOperation and Economics in Transport

Malaya Mohanty, Madhu Lisha Pattanaik, Satya Ranjan Samal, Shivam

Communications - Scientific Letters of the University of Zilina 2024, 26(3):A50-A65 | DOI: 10.26552/com.C.2024.033  

This study explores the significant role of three-wheelers (3W) on urban road traffic, focusing on the reduction in average vehicle speeds and its consequential impact on the Level of Service (LOS) of the road. Data collected from various traffic volumes reveal significant speed reductions ranging from 4 % to 35 % due to the movement of 3Ws on the road. To model this phenomenon, Artificial Neural Network (ANN) is employed. The resulting reductions in speed, induced by the 3W, trigger LOS degradation, leading to congestion and delays. A noteworthy finding is that the traffic flow naturally gravitates towards the LOS C, underscoring the substantial role...

Increasing the Traffic Safety Level of Rolling Stock by Wheel Condition Monitoring Using an Automated Measuring ComplexMechanical Engineering in Transport

Sergii Kliuiev, Stanislav Semenov, Evgeny Mikhailov, Ján Dižo, Miroslav Blatnický, Vadym Ishchuk

Communications - Scientific Letters of the University of Zilina 2024, 26(3):B167-B174 | DOI: 10.26552/com.C.2024.031  

The rail rolling stock undercarriage condition monitoring is proposed by using an automated measuring system, located on the railway track and measuring the specified parameters of the wheels directly, while the train is moving. Regular undercarriage condition monitoring reduces the costs of preventive maintenance of rolling stock without compromising the traffic safety. An algorithm has been developed for the operation of a special software package for visualizing and assessing monitoring data on the condition of the undercarriage of rail rolling stock. The software package consists of separate software modules that can be used independently of each...

Generalized Ordered Logit Model with Testing Assumptions: A Case Study of Using Urban Light Rail in BursaCivil Engineering in Transport

Nurten Akgun, Tiziana Campisi, Muhammed Talha Sunar

Communications - Scientific Letters of the University of Zilina 2024, 26(3):D38-D51 | DOI: 10.26552/com.C.2024.028  

Logistic regression has been a widely used prediction technique to analyze categorical variables. However, if the assumptions are violated the results may be biased. The study in this paper applied an analytical technique namely generalized ordered logit model. A case study of using urban light rail under pandemic conditions was applied for the analysis. The results suggested that logistic regression should not be applied before exploring the multicollinearity and applying the test of parallel lines. If the assumptions are violated, generalized ordered logit model should be considered. Regarding the predictive variables, sociodemographic, socioeconomic...

A Particle Swarm Optimization Based Fuzzy Flcpi-Pso Controller for Quadcopter SystemElectrical Engineering in Transport

Mohammed Baba, Fateh Bounaama, Sid Bennaceur, Aissa Benhammou, Mohammed Amine Soumeur

Communications - Scientific Letters of the University of Zilina 2024, 26(3):C9-C20 | DOI: 10.26552/com.C.2024.027  

The quadcopter persist as important roles across diverse applications, and the enhancement of their control efficacy has been the subject of extensive research. In this work, the authors proposed optimal Proportional Integral (PI) controller based Fuzzy Logic Control (FLC) for the roll, pitch, altitude, and yaw motions of the quadcopter system. The proposed technique uses the Particle Swarm Optimization (PSO) algorithm to tune the parameters of the FLC and enhance the quadcopter performance. The simulation results show that the proposed technique achieves smoothness of control and significant improvement over classical techniques, as the rise...

Pits Transporting System from Pitter Fruit Machine - Case StudyMechanical Engineering in Transport

Łukasz Nowakowski, Piotr Kurp, Michał Skrzyniarz, Sławomir Błasiak, Wojciech Depczyński

Communications - Scientific Letters of the University of Zilina 2024, 26(2):B128-B134 | DOI: 10.26552/com.C.2024.025  

The paper presents the construction and technological aspects of a device for pitting fruit, especially cherries, on an industrial scale. The presented work includes design solutions related to the transport of pits removed from pitted fruit, as well as a gravity chute, with an indication of potential operational problems related to the machine design. The authors proposed the use of a screw conveyor, especially in the case of longer drums, to optimize the process. Some analyses are also presented, including friction occurring during the transport of pits. Ultimately, a specific design concept is presented that integrates the screw conveyor with...

The Service Life Prediction for Brake Pads of Freight WagonsMechanical Engineering in Transport

Sergii Panchenko, Juraj Gerlici, Alyona Lovska, Vasyl Ravlyuk

Communications - Scientific Letters of the University of Zilina 2024, 26(2):B80-B89 | DOI: 10.26552/com.C.2024.017  

The analysis of the statistical values of wear of brake pads in operation, based on which a wear model was developed, is presented in this paper. This model can be used for predicting the remaining service life of brake pads according to the wagon mileage. The distribution function of wear on the upper and lower parts of the pad was determined, which made it possible to find the main qualitative characteristics, namely, the wear intensity, the γ-percentage wear, and the average pad wear at a specified wagon mileage. The results of the study can be factored for solving complex engineering problems of excessive wear of composite...

Peculiarities of Designing the Frame of a Universal Container Made of Rectangular PipesMechanical Engineering in Transport

Juraj Gerlici, Alyona Lovska, Mykhailo Pavliuchenkov, Oleksandr Kravchenko

Communications - Scientific Letters of the University of Zilina 2024, 26(2):B72-B79 | DOI: 10.26552/com.C.2024.016  

The features of designing the frame of a universal container made of square pipes are presented in this paper. The two frame loading schemes are taken into account: the effect of vertical loading on the container frame when it is lifted by the upper corner fittings (I loading mode); the effect of longitudinal loading on the frame during transportation by the rail transport (II loading mode). Mathematical modeling was performed to determine the longitudinal loading acting on the container in the II loading mode. The determined acceleration is taken into account when constructing the schemes of force factors that arise in the frame. The strength...

Comparison of the Molding Parameters Effects on Metal Injection Molded Specimens in the Real Experimental and Simulation EnvironmentsMechanical Engineering in Transport

György Ledniczky, Zoltán Weltsch

Communications - Scientific Letters of the University of Zilina 2024, 26(2):B90-B98 | DOI: 10.26552/com.C.2024.018  

This article presents a technology that is not widely known. Previous research has investigated the effect of metal injection molding parameters on product shrinkage. The technology is mostly limited by the variations caused by deformation, so it is of paramount importance to focus on shrinkage. Consequently, within this study the injection molding simulations with 17-4PH type material was performed and its results were compared to the previously determined curve characters. The results obtained allow conclusions to be drawn regarding the accuracy of the simulation. Changing the parameters of the injection molding process can significantly affect the...

Effect of Environmental Conditions on Curing of Polyurethane Adhesive Investigated with Ftir AnalysisMechanical Engineering in Transport

Péter I. Kovács, Zoltán Weltsch, Miklós Berczeli

Communications - Scientific Letters of the University of Zilina 2024, 26(2):B118-B127 | DOI: 10.26552/com.C.2024.024  

The use and significance of adhesives in various industries are explored, highlighting the growth of the adhesive market and the crucial role of time in adhesive bonding. The composition of adhesives, particularly polyurethane adhesives (PUR), is detailed, emphasizing their sensitivity to environmental factors, like moisture and UV radiation. Various factors influencing adhesive properties, such as reactivity and curing-induced shrinkage, are discussed, along with the importance of catalysts in adjusting reaction rates. One-component moisture-curable PUR adhesives are presented as versatile and continually improving alternatives in structural adhesive...

Development of the Bonding Technology of Modern Automotive Materials with Environmentally Friendly SolutionsMechanical Engineering in Transport

Zoltan Weltsch, Ferenc Tajti, Miklós Berczeli

Communications - Scientific Letters of the University of Zilina 2024, 26(2):B135-B141 | DOI: 10.26552/com.C.2024.026  

The significance of bonding technology for modern vehicle structural materials is increasingly acknowledged, driven by the adoption of new materials to reduce weight. This is important not only for quality and economic reasons but to address environmental pollution, as well. Traditional joining methods like riveting, screwing, welding, and brazing, are often unsuitable or limited for modern materials. Soldering, an economical and almost waste-free technology, is becoming more widespread. Through optimization, it achieves a strong, durable bond. There is a potential to favourably alter interface properties, including using high energy density surface...

Improving the Energy Efficiency of Operation of a Multi-Motor Plate Conveyor in the Steady-State Operation ModeElectrical Engineering in Transport

Adilbek Kazbekovich Kelisbekov, Nurlan Asylkhanovich Daniyarov, Baurzhan Gilymovich Moldabaev

Communications - Scientific Letters of the University of Zilina 2024, 26(2):C1-C8 | DOI: 10.26552/com.C.2024.022  

The established mode of operation of the conveyor with a nominal linear load is the most economically advantageous from the point of view of increasing the energy efficiency of mineral transportation, in which the cargo flow with minerals corresponds to the nominal productivity of the conveyor. An increase in the linear load of the working branch of the traction-bearing body to a nominal value reduces the share of unproductive consumption due to which energy savings are achieved for a certain period of time, characterized by its hourly average value.

Estimation of Vulnerable Road User Accident Frequency through the Soft Computing ModelsManagement Science and Informatics in Transport

Saurabh Jaglan, Sunita Kumari, Praveen Aggarwal

Communications - Scientific Letters of the University of Zilina 2024, 26(2):E1-E11 | DOI: 10.26552/com.C.2024.023  

Accident prediction models are mathematical expressions or algorithms used to determine the causal factors for road accidents and road safety engineers are using these models, as well. Modelling this kind of accident is quite challenging and required good quality of data. The results of the artificial neural network model, Gaussian processes model, and support vector machine model are compared for vulnerable road accident frequency in this study. The accident frequency dataset comprises 218 records, with 146 designated for training purposes and 72 reserved for testing. The model's accuracy was contingent on: the mean absolute error, root mean square...