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EN
Passenger cars are a means of transportation used widely for various purposes. The category that a vehicle belongs to is largely responsible for determining its size and storage capacity. There are situations when the capacity of a passenger vehicle is not sufficient. On the one hand, this insufficient capacity is related to a paucity in the space needed for stowing luggage. It is possible to mount a rooftop cargo carrier or a roof basket on the roof of a vehicle. If a vehicle is equipped with a towbar, a towbar cargo carrier can be used for improving its space capacity. These accessories, however, offer limited additional space, and the maximal load is determined by the maximal payload of the concerned vehicle. If, on the other hand, there is a requirement for transporting a load with a mass or dimensions that are greater than what could be supported using these accessories, then, provided the vehicle is equipped with a towbar, a trailer represents an elegant solution for such demanding requirements. A standard flat trailer allows the transportation of goods of various characters, such as goods on pallets, bulk material, etc. However, the towing of a trailer changes the distribution of the loads, together with changes of loads of individual axes of the vehicle–trailer axles. The distribution of the loads is one of the key factors affecting the driving properties of a vehicle–trailer combination in terms of driving stability, which is mainly a function of the distribution of the load on the trailer. This research introduces a study into how the distribution of the load on a trailer influences the driving stability of a vehicle–trailer combination. The research activities are based on simulation computations performed in a commercial multibody software. While the results presented in the article are reached for a particular vehicle–trailer combination as well as for a particular set of driving conditions, the applicability of the findings can also be extended more generally to the impact that the load distributions corresponding to various vehicle–trailer combinations have on the related parameters and other driving properties.
EN
This work is focused on the possible ways of improving the running safety of a railway vehicle, which uses IRWs (independently rotating wheels) in a bogie. It discusses the main positive and negative properties of an application of IRWs for a railway vehicle while it is running in a curve. There are evaluated running properties of a railway vehicle in terms of safety for IRWs and a standard wheelset (SW). It is assumed that a wheelset design with IRWs will reduce the risk of derailment of a railway vehicle in a curve with a smaller radius because it will be reached a more favourable distribution of decisive forces in the wheel/rail contact. A designed wheelset with IRWs differs from other IRWs designs; in this case, only a flange can rotate independently from a wheel treat surface about the axis of rotation. Further, this research presents an analysis of a friction forces distribution of the friction forces in a contact of a flange and a rail head and a comparison with an SW. The obtained results allow concluding that it is advisable to use the wheels with the perspective wheel design (including independently rotating) to reduce the resistance to movement and improve the running properties of a railway vehicle for safety.
EN
The predominant goal of the research presented in this paper is the design of a manipulator for a conveyor of bulk materials based on the given requirements. This issue is an emerging topical one mainly for the reasons of increasing efficiency and speed, as well as the safety of maintenance of machines and equipment. Especially, another essential aspect is the reduction of the physical strain on operators during service operations on the conveyor of bulk materials. The introductory part of this paper attends to the materials used for the production of steel structures, their technological processing, as well as different types of joining of their components. The practical part was set out to ascertain the mass and position of the center of gravity of the load itself – the conveyor. From the perspective of acting, it loads the entire proposed structure, although in different operating modes.
EN
The paper is a continuation of the issue of the technical solution of a mast type jib crane for handling sludge pumps. It serves for the use in Building no. 900, Block V2, of the nuclear power plant Jaslovské Bohunice. It is an optimization of the original, in-service damaged handling device with manual control of lift and rotation. The overloading of the device has an insignificant effect on the lifting force on a crank handle. It was found that the lifting force permanently falls within the recommended range of 120 to 160 N for convenient operation by a single worker. Inasmuch as there is a complete absence of bearings in the slewing gear in the original design, it is the solution to this issue that is the subject of the paper. The problem of pulling out the sludge pumps, which was established in the course of using the jib crane, ingeniously provided the opportunities to further design changes on the original design. The solution offered was to scrap the original design of the carrier inserted into the support and replace it with a fixed mast on which the boom would rotate. Accordingly, it would potentially be feasible to increase the load capacity of the jib crane, and thus the issue of the sludge pumps attached to the tank bottom would be solved. Moreover, it is attainable to extend the scope of this crane in this way.
5
Content available Strength analysis of an off-road lorry frame
EN
The lorry frame is the main carrying part of a lorry, composed of several components. These components are connected by joints into one structural unit and it forms the lorry chassis. The contribution of this article is focused on thestrength analyses of a backbone frame, which is used on an off-road lorry chassis. Strength analyses are carried out utilising the finite element method. This article presents a created three-dimensional model of the frame and definition of boundary conditions (loads, the definition of degrees of freedom) needed for simulation computations. Results of the numerical calculations are the main parts of this article. Attention is mainly centred on the distribution of stresses of the frame under defined loads and its deformations.
EN
This article is aimed at the engineering design of a manipulator, which is pneumatically controlled. It will serve for mounting the compressor of an air suspension system to the chassis of a sport utility vehicle (SUV) produced in the Slovak Republic. The manipulator will be used on an assembly line, on which SUVs are assembled. The designed device belongs to a group of dedicated devices, which are not produced within a serial production, however, it is the only functional prototype. Together with the manipulator structure, a pneumatic part of the assembly line including individual components, schemes and the pneumatic system will be proposed. Within the project process, all necessary customer demands, technical and safety standards have to be met. Moreover, ergonomic requirements for handling the device and other acts on the workplace have to be considered.
EN
The article deals with a FEM analysis of main parts of an engineering design of a pneumatically controlled manipulator, which will serve for mounting a compressor to a PO536 car chassis. This car chassis belongs to SUV cars and it is equipped with a pneumatic suspension system. It is the chassis of a Porsche Cayenne car produced in the Slovak Republic. The designed manipulator will be located on the assembly line of this vehicle. Except of FEM analyses of designed important parts of the manipulator, which are necessary for verification of safety of the design in order to obtain distribution of stresses and deformations in a structure, the it contains also the design of a pneumatic circuit of the manipulator together with pneumatic logic and it individual components. Based on three-dimensional model, there will be possible to generate drawings of the manipulator for manufacturing of the device and its application to the real operation.
EN
This article discussed the determination of a metro vehicle’s door forces acting on its coarse structure. With previous articles addressing this issue, a definition of a specific reference vehicle was provided together with the collection of the normative requirements for metro vehicles. These form a basis for addressing the issue. The main objective hereof was to design a technical solution of a door system for the reference vehicle and create a parametric model of the door's forces acting on the vehicle’s rough structure. This model would serve to approximate and operatively quantify these force effects of the door to the vehicle’s structure by modifying the various input parameters. Therefore, it was necessary to create a mathematical model of the equilibrium conditions of the proposed door system and to quantify them using a developed software. Subsequently, these results served as inputs for the FEM analysis of the load-bearing components between the door and the vehicle’s structure.
EN
This contribution is focused on an engineering design of main components of a door system intended to be mounted on an underground railway vehicle. The design has to take into account the operational and normative requirements for the underground railway vehicle's outer door. The design of main dimensions of a door will serve as input data for creation of a virtual model and it will be used to determine the load conditions for the numerical simulation in terms of strength. The aim is using this preparation to obtain all the necessary data entering the analytical calculations for setting up a parametric model, which will serve as a base for possible derivation of the designed structure.
PL
Głównym tematem pracy jest inżynierski projekt głównych elementów systemu drzwiowego przeznaczonego do zamontowania w podziemnym pojeździe kolejowym. Projekt musi uwzględniać wymagania operacyjne i normatywne dla zewnętrznych drzwi pojazdu kolejowego. Zaprojektowane główne wymiary drzwi posłużą jako dane wejściowe do stworzenia modelu wirtualnego, co zostanie wykorzystane do określenia warunków obciążenia dla symulacji numerycznej pod względem wytrzymałości. Celem jest wykorzystanie tych symulacji do uzyskania wszystkich niezbędnych danych wprowadzanych do obliczeń analitycznych w celu utworzenia modelu parametrycznego, który posłuży jako podstawa do wykonania zaprojektowanej struktury.
EN
This contribution introduces process and results of assessment of the ride properties of a tricycle in terms of driving safety as well as in terms of ride comfort for passengers. The analysed tricycle has been designed at the authors’ workplace. Ride comfort for passenger of road vehicles is one of the most important performances of a vehicle. The research of automotive passenger ride comfort is still very important. Values of vertical wheel forces were evaluated as critical parameters for assessment of driving safety and values of total accelerations were assessed in terms of ride comfort. At the same every vehicle has to meet quite strict criteria for driving safety. All calculation and evaluation of results were carried out by means of multibody software package.
PL
Praca prezentuje proces oceny i wyniki badań właściwości jezdnych pojazdu trójkołowego pod względem bezpieczeństwa jazdy, a także pod względem komfortu jazdy dla pasażerów. Analizowany trójkołowiec został zaprojektowany w miejscu pracy autorów. Komfort jazdy dla pasażerów pojazdów drogowych jest jednym z najważniejszych parametrów pojazdu. Badania komfortu jazdy pasażerów samochodów są nadal bardzo ważne. Wartości sił pionowych kół oceniono jako parametry krytyczne do oceny bezpieczeństwa jazdy, a wartości przyspieszeń całkowitych oceniono jako najważniejsze w kwestii komfortu jazdy. Jednocześnie każdy pojazd musi spełniać dość surowe kryteria bezpieczeństwa jazdy. Wszystkie obliczenia i oceny wyników przeprowadzono za pomocą pakietu oprogramowania wieloobiektowego.
EN
The contribution presents a modification of a goods wagon bogie frame. Every newly designed or significantly modified any support part of a railway bogie must meet strict criteria related to its strength and fatigue life. It presents key changes of the structure of an original goods wagon bogie frame, conditions and results strength analyses for unfavourable load cases, for which values of load forces come out from valid standards. The introductory part presents the original goods wagon bogie and the idea of its modification. In the next part analyses of structural properties (modal and stress analyses) are introduced. Simulation computations were carried out using Finite Element Method. Further, main load cases which all bogies must meet before commissioning and conditions for bogies approval are described. In simulation calculations a goods bogie frame was loaded in compliance with standards by four unfavourable load cases.
EN
Vibration properties of road vehicles can be in principles evaluated using two ways, i. e. by simulation computations using a virtual model of a vehicle and by measuring on a real vehicle prototype, whereby, their dynamical properties are usually assessed in compliance with to two criterions, namely from the ride comfort for passengers point of view and from the driving safety point of view. The topic of this article is focused on evaluation of passenger’s ride comfort of a tricycle. In this regard, vertical movements of a vehicle are most important. In respect of ride comfort for passengers, accelerations in vertical direction are critical. Accelerations are usually detected on a seat. In regard of driving safety, value of the contact force between a wheel and a road are decisive. In our research we present process of investigation of level of ride comfort for passengers and level of driving safety of a tricycle based on simulation computations using the tricycle multibody model.
EN
Soybean meal is one of the fodder components. It is a by-product of the production of soybean oil. Soybean meal is a specific cargo due to changes that may occur in it during transport processes. These changes are subject to many distinguishing features of usable quality inter alia fat and fatty acid content. The temperature and size of the soybean meal particles are among the factors influencing the transformations. The article presents the results of research on soybean meal and its individual fractions and the impact of selected indicators on the quality changes of this cargo. The results depend on the conditions corresponding to those that occur during the storage, handling and transport processes. The dependencies between them have been determined. The performed research allowed to determine the type and scope of changes taking place in this cargo under the influence of temperature. The results of the study showed that as the temperature rises, the fatty acid content in the soybean meal decreased during storage for a given period of 30 days.
EN
The influence of external factors on changes in the soybean meal quality features has an important meaning in the emergence of hazards during the transport processes of this cargo. Soybean meal is one of the most frequently used components of fodder mixtures. Due to its inherent properties, it is classified as special cargoes. Maintaining the quality of soybean meal during transport processes depends on storage, handling and transport conditions. The main external factor included in the study was humidity. Transport-technological quality features were distinguished: kinetic angle of repose, size of particles, bulk density, porosity. The article presents the results of research on soybean meal and its separated fractions. There was presented humidity influence on changes in significant features for this cargo. Type and range of changes in the distinguishing features of soybean meal were determined in the given stages of the transport chain under the influence of humidity. The risk was assessed in the transport processes of soybean meal. A correlation was determined between changes of individual features and water content in soybean meal changing as a result of air humidity. It was found that humidity of the ambient air in which transport processes occur and size of grain particles of soybean meal have a significant impact on changes in transport-technological quality features.
EN
The aim of this investigation is to evaluate the influence on fatigue behavior of the welded aluminum alloy AlMgSi07. For the experimental measurement of fatigue of these welds, it is needed to analyse all the changes, which will occur in the weld material in comparison with the basic material. The modern computer simulation and the experimental verification are strong tools for achievement of the required results, for instance a change of the structure, residual stress, a range of the heat affected zone, a deformation of the workpiece etc.
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