<p style="text-align: justify;">Pressure vessels that are exposed to high stresses, due to unfavorable working conditions during exploitation, must be properly designed, taking into account all calculation factors, in order to be safe during their expected lifetime. Checking the condition of the vessel, or analyzing the load of the vessel in working and test conditions, is mandatory. In recent times, numerical analysis represents one of the most important methods of analyzing the stress states of all structural elements, including pressure vessels. It enables precise determination of the location of the greatest stresses and deformations. In this paper, a stress analysis of a vertical cylindrical pressure vessel type VS 110 with a spiral for heating and cooling, with a volume of 3750 liters and a working pressure of 3 bars, which is used for the preparation of medicines in the pharmaceutical<br />industry, was performed. The calculation of the vessel was made according to the EN 13445 standard and regulations on pressure vessels. Then a numerical stress analysis was performed in the Autodesk Inventor 2023 software package. The results of the numerical analysis show that the highest stresses occur in the torispherical parts of the vessel end. Furthermore, the cylindrical nozzles on the shell as well as on the torispherical ends act as a reinforcement of the vessel because there is a stress reduction in their vicinity.</p>

This paper brings the introduction of the analysis of foundation solution for the noise protection walls on the reinforced earth along the Highway Corridor Vc, a road and rail transport corridor that connects Hungary, Croatia and Bosnia and Herzegovina, included in the network of Pan-European transport corridors. A solution with pile foundations made of steel IPE profiles is presented in detail. During the design and modelling, as well as the calculation of the structural foundation, the modern software program PLAXIS was used, and the calculation was made in accordance with EN 1997 Eurocode 7, Geotechnical Design. Special attention is devoted to the analysis of the impact of driving IPE steel profiles, as foundation piles, on reinforced earth. The presented solution was then verified by an additional control calculation and a field test of the impact of the horizontal load on the bearing capacity of the IPE steel profile driven into the reinforced slope. Based on the conducted analyses and testing, it has been proven that it is possible to build noise protection walls on the reinforced earth without disturbing the internal stability and functionality of the reinforced earth.

The paper presents the engineering practice, which the company “Regeneracija” Ltd. Velika Kladuša – Bosnia and Herzegovina uses to perform preliminary experimental testing and measurements, followed by mathematical modeling of critical pressure of these vessels, in order to obtain the projected quality of pressure vessels made of composite materials. The paper will confirm the hypothesis that it is possible to relate mathematical connection and dependence of the critical pressure of vessels of composite materials (Pkr) with mechanical characteristics of vessel material (σM), vessel diameter (D), and vessel wall thickness (s). In this way, by varying the mentioned parameters, it is possible to achieve the desired product quality in the production of composite material containers by achieving the projected critical and thus working pressure. Generally speaking, the mathematical model of critical pressure obtained in this way will be a good indicator for design engineers to know how much critical pressure a given vessel can withstand, and based on that to take quick control of working or projected pressure, but also for designing completely new vessels made of composite materials as a substitute for the expensive experimental testing.

<p style="text-align: justify;">Mechanical properties of every material play important role during material selection for any mechanic system. The main mechanics property which is crucial for material selection is Toughness. The paper present some of the aspects in problems of the toughness and fatigue for Aluminum Alloys. The paper also presents the set of the ASTM anf British<br />Standards which describe procedure in analysing and determining toughness and fatige properties for this kind of the alloys.</p>