Denis Molnár

Mr. Denis Molnár

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2022 in Communications - Scientific letters of the University of Zilina
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Journal Article
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Ján DižoJán Dižo
Ján Dižo
Miroslav BlatnickýMiroslav Blatnický
Miroslav Blatnický
DMDenis Molnár
Denis Molnár
AFAnatoliy Falendysh
Anatoliy Falendysh
Freight wagons are among the most widely used means of transporting goods by land. Such a number of wagons and transported material and amount of material need to meet requirements in terms of safety and reliability. A wagon bogie is a key ele...

15 May 2022 in Manufacturing Technology
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Journal Article
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DMDenis Molnár
Denis Molnár
Miroslav BlatnickýMiroslav Blatnický
Miroslav Blatnický
Ján DižoJán Dižo
Ján Dižo

18 August 2023 in Machines
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Miroslav BlatnickýMiroslav Blatnický
Miroslav Blatnický
Ján DižoJán Dižo
Ján Dižo
Milan SagaMilan Saga
Milan Saga
DMDenis Molnár
Denis Molnár
Aleš SlívaAleš Slíva
Aleš Slíva
Current trends in the transportation industry prioritize competitive rivalry, compelling manufacturers to prioritize concepts such as quality and reliability. These concepts are closely associated with public expectations of safety, vehicle lifespan, and trouble-free operation. However, the public must recognize that a vehicle weighing several hundred kilograms, moving at a non-zero speed, only contacts the road surface through a few points (depending on the number of wheels), each no larger than a human palm. Therefore, it is imperative to operate the vehicle in a manner that optimizes the behavior of these contact points. There are situations where drivers find themselves requiring dynamic vehicle handling, often unpredictable with a high degree of uncertainty. Rapid changes in direction become necessary in these cases. Such maneuvers can pose a significant risk of rollover for three-wheeled vehicles. Hence, the vehicle itself should contribute to increased ride safety. This paper presents key findings from the development of an unconventional three-wheeled vehicle utilizing the delta arrangement. Rollover safety for three-wheeled vehicles is currently well-managed, thanks to the utilization of electronic or mechatronic systems in delta-type vehicles to enhance stability. However, these systems require additional components. In contrast, the proposed control system operates solely on a mechanical principle, eliminating operational costs, energy consumption, maintenance expenses, and similar factors. The study also explores the absence of equivalent suspension and steering systems for front-wheel steering. Such designs are lacking in both practical applications and theoretical realms. Analytical and simulation calculations are compared in this study, highlighting the effectiveness of the newly proposed control system in enhancing stability and safety compared to conventional front-wheel suspension systems. Simulation programs provide more realistic results than analytical calculations due to their ability to account for dynamic effects on vehicle components and passengers, which is practically unfeasible in analytical approaches. Furthermore, this study focuses on investigating the fatigue life of material frames subjected to dynamic loading, which is a crucial aspect of ensuring safety. It is essential to have various testing devices to examine the fatigue life of materials under both uniaxial and multiaxial loading conditions. However, obtaining experimental results for fatigue life measurements of specific materials, which can be directly applied to one’s research, poses significant challenges. Hence, the proposed testing device plays a vital role in measuring material fatigue life and advancing the development of unconventional transportation methods. The information about the original testing device aligns perfectly with the article’s emphasis on dynamic analysis. The ultimate objective of all these efforts is to put the vehicle into practical operation for commercial utilization.

30 December 2021 in Perner's Contacts
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DMDenis Molnár
Denis Molnár
Miroslav BlatnickýMiroslav Blatnický
Miroslav Blatnický
Ján DižoJán Dižo
Ján Dižo
A bridge crane is a type of crane that is designed for lifting / lowering and transferring material in the horizontal direction and is used mainly in production halls, warehouses and transship points. A part of the lifting mechanism of the bridge crane is a crane hook on which the load is suspended. Sufficient strength is required from the crane hook in order to be able to withstand high loads relatively well. The most stressed part of the crane hook is the curved inner surface. This surface is considered critical in terms of strength. The goal of this paper is to select a suitable crane hook for a single girder bridge crane with a load capacity of 500 kg and a strength analysis of the selected crane hook. Strength analysis is performed by two methods, first is based on analytical calculation and second is based on finite element method (FEM) performed in Ansys software. The comparison of the obtained total stresses from both methods is the part of the analysis. From the results of the FEM analysis and analytical calculation it can be stated that the selected crane hook RSN 05 P - DIN 15401 with a load capacity of 500 kg is suitable for the above-mentioned bridge crane. It can also be concluded that the total stress determined by the analytical calculation is lower by 9.8 % compared to the stress obtained from the Ansys software.

9 December 2023
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Book Chapter
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Miroslav BlatnickýMiroslav Blatnický
Miroslav Blatnický
DMDenis Molnár
Denis Molnár
VIVadym Ishchuk
Vadym Ishchuk
ASAndrej Suchánek
Andrej Suchánek

15 December 2022 in Materials
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Miroslav BlatnickýMiroslav Blatnický
Miroslav Blatnický
Ján DižoJán Dižo
Ján Dižo
DMDenis Molnár
Denis Molnár
ASAndrej Suchánek
Andrej Suchánek
This paper focuses on the development, theoretical and experimental research on the structural units of an unconventional three-wheeled vehicle. The vehicle is designed in order to increase the stability when cornering in a low curvature radius. Current research work describes solutions to increase the cornering stability of either conventional three-wheeled vehicles or, more rarely, unconventional vehicles designed on the basis of complex wheel-tilting mechatronics. Thus, there is a gap in research in respect of consideration of a stability-enhancing mechanism for three-wheeled vehicles based on a combination of tilting and deflection of the front steered wheel in the course of cornering. This paper then compares the stability of a three-wheeled vehicle with one steered wheel in front and two wheels in the rear (1F2R) in conventional and unconventional designs. A particular linear formula for the stability of the three-wheeled vehicle in cornering is derived. This study further deals with the design of the frame intended to hold the unconventional steering mechanism of the front wheel of the vehicle, on the one hand, from the theoretical integrity point of view using CAD-, FEM- and MBS-based software and, on the other hand, from the experimental point of view by determining the multiaxial fatigue life of the test specimens. These were made from the frame structural material and loaded with an equivalent load (bending-torsion) corresponding to the real load of the frame in operation. It was discovered that the designed patented front wheel steering mechanism increased the passing speed by 19% in comparison with a conventional vehicle at the minimum possible radius of a corner. The designed vehicle meets the safety conditions in terms of frame integrity and load-bearing capacity. The vehicle frame is designed with respect to the fatigue life of the material, the results of which are presented in the work. The material employed for manufacturing the frame is aluminum alloy type EN AW6063, which makes the frame lightweight and strong.