International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This report presents an approach for predicting energy consumption in a specific living space based on experimental data on the indoor microclimate. The data for the analysis of the temperature in the room and the external temperature of the environment is used for the period from 01.01.2016. until 31.12.2023, and a period of 18:00 – 24:00. Regression analysis is used to create a model for increasing energy consumption.

Damage to the turbocharger of the 8400kW diesel engine, which had operated about 66 640 running hours, has caused off hire of the vessel for 10 days and the turbocharger repair had cost more than half a million euros. The study performed on this work consi sts of evaluating the consequences of the low turbocharger performance on the fuel oil consumption and the reasons for this. Specific data were collected and analysed in order to create an appropriate mathematical model between the studied parameters. Measurements and data collected were performed a month before turbocharger damage and after the TC overhaul (with new cartridge). As results can be concluded that losses in turbocharger performance is very important for the efficient operation of the main engine, they must be monitored and analysed.

An experimental study of the geometrical characteristics of the cross sections of the thermally affected areas obtained by electron beam welding of carbon steel 45 is made. The thermally affected zone and the molten area of the welds from non-stainless steels corresponds to a zone where the physical-mechanical properties and the microstructure of the processed material are changed after the processing. The process parameters that were changed during the experiments are: welding speeds were 0.5, 1.0 and 1.5 cm/sec, the beam current was changed in the range of 30 – 133 mA and the focus position was changed from 72 mm above the sample surface to 62 mm below the sample surface. The accelerating beam voltage was 50 kV. The geometry of the weld in the cases of a deep penetrating electron beam and narrow thermally affected zone is investigated. Electron beam welding process parameter optimization is performed, based on the estimation of regression models. In such way the electron beam optical systems can be tested and the specific quality requirements for the welds obtained by electron beam welding can be fulfilled

The work is devoted to the study of evolution of flaws in aluminium alloys of Al-Zn-Mg-Cu, Al-Cu-Mg-Мn alloying systems and to the determination of their connection with structural factors of the material such as the size and composition of intermetallic phases conditioned by heat treatment tempers, and also to the study of the effect of big number of physical factors on the long-term behaviour of structural elements of aluminium alloys, and to the determination of the rate of formation of corrosion damages in structural elements of the aircraft wing

This article has experimental nature. The values of the dynamic elastic modulus (Young’s modulus) of gamma polymer concrete composites are determined quantitatively. The tested samples have the form of a rectangular parallelepiped (type bar).

The dynamic Young’s modulus of the samples is determined by the method of the experimental modal analysis. Impact excitation was applied for expressing the resonance frequencies in the tests of bending and twisting the sample. The test results were processed with regression analysis.