The paper presents a proposition of a new method for calculating the damage degree of electric pylon model by fuzzy logic application. Damage changes in constructions manifest themselves in small but detectable variations of frequency. The change of the speed of wave propagation, which is associated with the change of the natural frequency in the system, is caused by the deformation of the examined material. This phenomenon can be used for an indirect analysis of the construction damage. The main aim of the article is presentation of the results of the vibrations analyse of the electric pylons. In the preliminary tests the research was conducted on the simulation data of the electric pylon of power grid. Eight construction elements of pylon in different positions were chosen to simulate the damage by decreasing step by step the Young's modulus. The simulation data was obtained on the basis of the stiffness matrix updated in conjunction with the Finite Element Method. The preliminary research presented in the paper is aiming at creating the software which can monitor in real time the state of electric pylons.

Using statistical energy analysis method to gain knowledge of coupling loss factors (CLFs) of structural elements of complex mechanical systems is fundamental, therefore the evaluation of CLFs for different constructional connections of thin rectangular plates merits studying. CLFs for different constructional perpendicular connections of thin rectangular plates were investigated. Three types of couplings were studied: line junction, stiff bridges, and point connections. Investigations were realized with method of energy stored at anechoic chamber. Experimental test included two kinds of connections of tested perpendicular plates: welded line junctions and point junctions. Several combinations of thickness ratio on CLFs values were tested for welded plates. Also, the distribution points were studied to show the impact on CLFs. There is evidence of decreasing of CLFs for larger ratios of thickness especially for higher frequency bands. Acoustic power flow across riveted junctions shows up to 20 dB lower transmission than similar spot welded junctions. In the examined screwed junctions demonstrate lower than average CLFs activity than riveted and higher than point welded.

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Реалізовано систему моніторингу і аналізу спектру віброприскорень на одноплатному мікрокомп'ютері Raspberry Pi 3 і трьохосьовому цифровому MEMSакселерометрі ADXL345. Система включає драйвер акселерометра під Raspberry Pi та програмне забезпечення для збору і опрацювання даних від давача прискорення. Програмне забезпечення перетворює виміряні сигнали віброприскорення з часової області в частотну використовуючи алгоритм дискретного перетворення Фур'є (ДПФ) та будує графіки віброприскорень і спектрів Ключові слова: система моніторингу віброприскорень, ADXL345, Raspberry Pi, спектральний аналіз, дискретне перетворення Фур'є Реализована система мониторинга и анализа спектра виброускорений на одноплатном микрокомпьютере Raspberry Pi 3 и трехосном цифровом MEMS-акселерометре ADXL345. Система включает драйвер акселерометра под Raspberry Pi и разработанное программное обеспечение для сбора и обработки данных с датчика ускорения. Программное обеспечение преобразовывает измеренные сигналы виброускорения из временной области в частотную, используя алгоритм дискретного преобразования Фурье (ДПФ) и строит графики виброускорений и спектров Ключевые слова: система мониторинга виброускорений, ADXL345, Raspberry Pi, спектральный анализ, дискретное преобразование Фурье

Despite growing number of literature demonstrating the piezoelectric effect in bones at macro level there's still a lack of papers describing this effect at molecular level. In order to examine this effect more specifically, a study has been conducted to show the possibility of using infrared spectroscopy on samples contained in the electric field. This is the first known research on applying infrared spectroscopy to study the influence of electric field and compressive stress on bones' structure represented by the molecular IR spectrum. The samples used in this experiment as a model were prepared in pellet form, made from powdered pig's shin bone mixed with KBr (mass ratio of about 1:100). The spectra were obtained in transmission mode. Three different types of experiments were performed at each sample, which were subjected to: (a) fixed electric field (E < 40 kV/m), (b) variable electric field (0-40 kV/m), (c) compressive stress (P < 100 MPa). The obtained data have shown that the electric field and compressive stress on sample modified infrared spectra of the bone. Qualitative as well as quantitative changes in the spectral range between 900 cm −1 and 1200 cm −1 and the band at 562 cm −1 (PO 3− 4 asymmetric and symmetric stretching, respectively) were observed. The relative area obtained by decomposition of the PO 3− 4band reaches an extreme value in the external compressive stress (10 MPa), that occur under physiological conditions. Based on presented data, it was proved that the applied factors (electric field, compressive stress) can change the oscillation energy and the number of molecule's degrees of freedom.

This paper concerns the idea of using magneto-mechanical effects in prophylactic activities to reduce the risk of occurrence of an extensive blackout on high voltage (HV) lines. The subject matter of the paper is related to the event from April 8, 2008, which deprived approximately 600,000 recipients from 18 cities of the West Pomeranian voivodeship of power and caused millions in losses for the national economy. In theoretical considerations, the idea of diagnosing the technical state and level of effort of steel power line towers using the metal magnetic memory method (MMM) is presented, with a consideration of the methodology for obtaining a reference signal from the external magnetic field. The capabilities of the MMM method have been illustrated by examples of active and passive experiments. Finally, the authors indicated the need of IT support of MMM data analysis using a 3D model of the predicted distribution of the magnetic field in the vicinity of the tested object.

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