Flight training is occupied by many hours of theoretical and practical training. Polish universities offer the possibility of conducting the aforementioned training as part of academic training. A young aviation student, implementing himself in this process, takes on the burden of academic training and aviation training. The aviation environment is sensitive to safety issues. These include the occurrence of incidents, events, and aviation accidents. This issue arises directly from the possibility of endangering the health and lives of bystanders as well as aviation personnel and the damage or destruction of aviation equipment. In addition, there are issues related to the immobilization of airports, aviation organizations, excess repairs, or cases settled in court. Despite all the above, it should be mentioned that air transport is described as the safest means of transportation where – although incidents, events, or high-profile crashes are occasionally recorded. It is desirable for personnel to remain as focused as possible during aviation tasks. The multitude of tasks carried out by aviation students, combined with the burden of academic study, can carry a significant impact on maintaining concentration, lowering perception, or at least meticulousness. These topics correlate closely with the human factor. As a research problem, the submitted work was adopted to determine the impact of academic teaching load on the safety of aviation activities performed, in the context of aviation training provided at universities. The research included aviation mechanics and aircraft crews within its scope.
Advanced high-strength steel (AHSS) is being used increasingly often in the structure of means of transport. Welds made of these steels can crack in the heat-affected zone (HAZ) and have inferior mechanical properties compared to the base material. The goal of this paper was to solve the technological and material problem of obtaining highstrengh thin-walled welded structures of AHSS steel designed for heavily loaded elements of transport means. The novelty of the article is its presentation of a modified welding process which enables a high-strength structure of the obtained joint to be obtained without welding defects and incompatibilities. Copper backing was selected as an effective method of heat dissipation in the process, and, using the basic solutions method, the leverage of a heat flow process in the weld method deposit (WMD) was checked after cooling down the substrate. The fundamental solutions method was used to determine the optimal shape of the backing. It has been shown that the new backing affects the structure and mechanical properties of welds. In order to verify the newly developed method, tensile tests of the obtained joint were carried out, the hardness was assessed, the metallographic structure was analyzed, and non-destructive tests were performed. The developed material and technological solution were used, for example, for the construction of the arm element of the mobile platform.
Natural gas is one of the potential combustion engine fuels whose proportion in the overall energy balance is expected to increase. Owing to some of its properties, its use requires a dual-fuel supply system; thus, the use of natural gas as a fuel for diesel engines is currently limited. Systems that supply gas fuel to diesel engines do not usually interfere with the engine control system. This solution significantly reduces system-installation costs. However, as demonstrated in the present study, it considerably changes the course of the combustion process, which increases thermal and mechanical loads. In this case, the combustion process can be controlled by changing the liquid fuel injection pressure or advancing the injection angle. This, however, requires interference with the engine control system.
Various types of structures and materials play an important role in the creation modern means of transport, including various grades of steel with different mechanical properties. For the rolling stock, proper operation and meeting the operational conditions is very important. Welded structures play an important role in the construction of various means of transport. Correct welding of carriages is important both in production and when carrying out various types of repairs. Each repair a carriage depends on its advancement and condition and the time of its operation. Each inspection for a refurbished carriage is defined either by the service life or the big distance traveled by the carriage. Important factor that may lead to damage is the effect of the load transported in the carriage. Therefore, the causes of the wear of the rolling stock are investigated and measures are taken to prevent any damage. The appropriate technical condition of the carriage also ensures safety on railroads for users and owners of the rolling stock. In the case of welded structures in carriages, it is influenced by poorly materials choice, incorrectly selected production processes and wrong selection of parameters. The goal of this paper is the mechanical properties analyse of weld low alloy steel structure of carriages after MAG welding using the parameters of the process. Thick-walled steel structures are used to build carriages, which is often a serious welding problem. The main role of welding conditions is connected with filer materials, welding technology, state of stress and temperature. In this paper, the properties of low alloy steel S3555J+N structures after MAG welding are presented. Furthermore, metallographic structure, tensile strength, bending test and impact toughness welded joints were analysed regarding welding parameters. The amount of acicular ferrite in WMD oxygen after welding was tested. Gas mixtures of argon and carbon dioxide with various percentage was used for shielding gas.
In the present work, biofuels produced from different raw fatty materials have been proposed as a dominant fuel component in biodiesel-diesel fuel blends. Biofuels were produced from pork lard and rapeseed oil by alkali transesterification using methyl alcohol. Blends of biofuels in volumetric proportions of 60 and 80% of the biocomponent and the remaining part of the conventional fuel were used in a compression ignition engine designed for medium-duty vehicles. The experiments were conducted at two engine rotational speeds (1500 and 3000 rpm, respectively) and a set of load conditions (50, 100, and 200 Nm, respectively). The tests focused on engine efficiency parameters (brake-specific fuel consumption and brake fuel conversion efficiency) as well as exhaust gas emissions (hydrocarbons, carbon monoxide, and carbon dioxide were determined). The obtained results indicate that blends containing biocomponents produced from pork lard were characterized by superior fuel consumption and efficiency results, compared to blends containing biocomponents produced from rapeseed oil. In terms of exhaust emissions, biocomponents produced from pork lard were also characterized by lower emission of all of the examined components compared to rapeseed methyl ester-diesel blends. This study proposes that fuel components obtained from custom (animal) raw-fatty material can be an effective substitute for commonly used rapeseed oil methyl esters.
There is an increasing demand for mixed joints made of hard-weldable steels used in the construction of transport means. An illustration of this is the welding of movable platform elements such as a pin to arm joints. The pin is made of high-strength structural steel S690 QL (1.8928) while the arm of the movable platform is made of DOCOL 1200M steel from the AHSS group (Advanced High-Strength Steel). Such a joint is not easy to make due to the different chemical composition of both steels. The difference in thickness of welded elements creates an additional difficulty. The thickness of the cylindrical pin is 40 mm, whereas the thickness of the sheet metal used for the platform arm is much smaller and amounts to 2 mm. Joints of varying thickness and chemical composition tend to produce cracks in the heat-affected zone as well as in the weld. The purpose of this article is to determine the most appropriate welding parameters and the selection of additional materials to obtain correct joint with good mechanical properties, free of welding defects and incompatibilities.
In the construction of mobile platforms, there is an increasing necessity to weld steels from the AHSS group (AHSS - Advanced High-Strength Steel) with low-alloy steels. This article verifies the possibility of obtaining accurate mixed welded joints from different grades of AHSS steel with S355J2 steel. The structure, as well as mechanical properties of the obtained welded joints, were thoroughly analysed.
In the mobile platform structure, there is an increasing necessity to weld steels from the various groups. For instance, it has become necessary to connect AHSS (Advanced High-Strength Steel) with fine-grained steels. This article verifies the possibility of obtaining accurate mixed welded joints from different grades of DOCOL 1400 steel (from the AHSS group) with S700 MC steel (from the fine-grained steel group). The structure, quality and mechanical properties of the obtained welded joints were thoroughly analysed. The joints were made at various welding speed with preheating to 80°C and without preheating.
The article presents the results of research of the Gwarek 1200 belt conveyor. The work aimed to determine the possible benefits of changing the type of rollers used. It was expected that the change of the rollers from N-type to C-type will reduce the costs of energy consumed by the conveyor drive system. This part of the research was carried out in a hard coalmine at the level of 665 m. The test was given the entire power unit in terms of the starting power demand and rated power in real time. Measurement works were carried out before and after the modernization of the conveyor for 5 years. Moreover, it was decided to extend the research to include vibroacoustic tests, aimed at determining the technical condition by measuring vibrations. It is expected that based on the analysis of vibration signals in the long term will allow to develop a method for diagnosing belt conveyor rollers and to quickly detect their malfunction under normal operating conditions.
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Steels of the DOCOL group, characterised by high tensile strength and yield point, play an important role in the manufacturing of means of transport. However, the above-named steels are difficult to weld and joints made in them do not guarantee comparable mechanical properties. The research work discussed in the article aimed to determine process parameters suitable for the welding of a moving platform made of steel DOCOL 1200M as well as to assess the effect of welding parameters on the quality of obtained joints. The tests also involved analysing the effect of shielding gases, preheating and interpass temperature on the quality of an 8 mm thick MAG welded moving platform structure.
PL
Ważnymi materiałami stosowanymi w budowie środków transportu są stale z grupy DOCOL, charakteryzujące się wysoką wytrzymałością na rozciąganie i granicą plastyczności. Stale te są trudno spawalne, a ich złącza nie gwarantują porównywalnych własności mechanicznych. Celem artykułu jest dobór parametrów spawania konstrukcji podestu ruchomego ze stali DOCOL 1200M. Postanowiono sprawdzić wpływ parametrów spawania na poprawność wykonanego złącza. Analizowano wpływ gazów osłonowych, roli podgrzewania wstępnego i temperatury warstw międzyściegowych na poprawność wykonanego złącza MAG konstrukcji podestu ruchomego o grubości 8 mm.
W artykule przedstawiono wyniki badań dotyczące wpływu stanu technicznego niektórych zespołów samochodu na przebieg opóźnienia hamowania. Przeprowadzono badania stanowiskowe oraz próby drogowe dla samochodów w stanie technicznym spełniającym wymagania prawne oraz z uszkodzonymi elementami, mogącymi mieć wpływ na proces hamowania. Badania drogowe przeprowadzono na jezdniach o różnych nawierzchniach. Omówiono wpływ stanu technicznego samochodu na przebieg procesu hamowania przy różnych prędkościach początkowych oraz na różnych nawierzchniach.
EN
The paper presents the results of investigation into the impact of the technical state of some car systems on the course of deceleration during braking menouvre. The cars were examined on the diagnostic stand and during road tests. The test were carried out for cars which meet the legal requirements and with failure elements which may affect the braking. Road test were carried out on different surfaces like dry and wet as phalt, snow and ice. Influence of technical conditions of cars on braking process on different road surfaces and the initial car speed has been discussed as well.
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