The article presents the results of a determination of the load attributed to rail vehicles transported by a ferry, considering the influence of sea waves on its hull. A mathematic model describing the displacements of a train ferry, which transported rail vehicles on its decks during rolling oscillations, was created. Calculated accelerations were used to identify the load of components from a dynamics point of view and they were subsequently applied as an input to the analysis of the strength of the open wagon main-bearing structure in a standard scheme of interaction with a train ferry deck. The calculated maximal equivalent stresses in the structure of the fastening units exceeded the valid permissible values. To confirm the theoretical results, experimental studies focused on the strength analysis of the open wagon placed on the railway ferry deck, which was performed in real operational conditions. Electrical voltage sensors were used to determine stress distribution in the areas where the body was attached to the deck. In this case, sensors of the strain gauges, i.e., tensiometers, were used. The base of 25 mm is a dimensional parameter and the resistance, 124 Ohms, is the tensiometer parameter. Verification has been performed and, based on the obtained experimental results, it has been established that the hypothesis’ adequacy is not rejected. The authors developed some measures for adaption of the lashing devices for rail cars on train ferries, which can ensure their safe transportation by sea. The strength calculation demonstrated that, in the new scheme of securing the transported railway vehicles on the railway train ferry, the stresses in its structure do not exceed the permissible values. The article also includes information about the results of the strength calculation of a container placed on a roll trailer transported by a train ferry. This research will contribute to the development of measures regarding the safety of railway vehicle transportation by sea ferry and better efficiency of train ferry transportation.
24 October 2023 in Communications - Scientific letters of the University of Zilina
The advantages and disadvantages of using the soft containers for cargo transportation are analyzed. The issues of the use of soft containers in transport and technological schemes for the supply of bulk goods are considered. Approaches to the...
Locomotives are important vehicles, which serve for towing wagons, i.e., trains. Many factors influence the safe and cost-effective operation of locomotives and trains in general. One of these factors is adhesion at the wheel/rail contact. The adhesion determines how much power the locomotive can deliver and how the braking system will ensure that the train stops. The main way to improve adhesion is to use sand at the wheel/rail contact point. The aim of this study is to improve the efficiency of the sand system of the locomotive. For this purpose, a new sand system nozzle mounting design was proposed. The newly proposed sanding system is equipped with a nozzle mounted to the axlebox unlike the original one, which uses the nozzle attached to the bogie frame. To compare the proposed and existing design, simulation calculations were performed in Simpack software 2024.3. For the simulation computation of the locomotive bogie, two types of railway tracks were chosen. A straight track section with two angular frequencies and three amplitudes of track irregularities was created, and a real track section corresponding to several kilometers of track was modeled in the Simpack software. During the simulations, it was determined that the proposed nozzle mounting design has a smaller amplitude of motion, compared to the existing one; therefore, there is a more accurate and efficient operation of the sand system. This in turn has a favorable effect on the adhesion of the wheel with the rail. It was found out that the newly designed sanding system has a significant positive economic effect regarding saving sand. There is no sand loss during sandblasting compared with the original sanding system. This directly relates to saving costs during locomotive operation.
11 July 2023 in Communications - Scientific letters of the University of Zilina
The presented article aims at assessment of the influence of test bench design on the cooling performance of a rail vehicle brake disc. The test bench is designed for experimental analyses of rail vehicles' brake components. The work includes ...
Nowadays, there is also a trend in rail transport to change to more environmentally friendly power cells. One such solution is the introduction of hydrogen fuel cells into the construction of rail vehicles. This paper studies the changes in the running properties of a modified rail vehicle and its components after replacing the standard diesel-electric powertrain unit with a new one using hydrogen fuel cells. This modification results in significant changes in the vehicle structure, especially in the mass and position of the centre of gravity of its various components. The running characteristics are analysed by simulation calculations using the commercial simulation software Simpack. A multibody simulation model consisting of rigid bodies connected by flexible force elements is used. This analysis is performed for both the original rail vehicle and the modified rail vehicle with hydrogen fuel cells. As a result, the modified rail vehicle with a hydrogen powertrain was found to have a similar force distribution in wheel/rail contact, but the axle load of this vehicle did not meet the criteria.