Wyniki wyszukiwania - Biblioteka Nauki

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Wibroakustyczna analiza zmian średnicy otworów w węzłach konstrukcyjnych masztów kompozytowych

100%

Dąbrowski Z. , Dziurdź J.

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tom nr 4

36-40

PL

Jednym z najbardziej istotnych i niewidocznych uszkodzeń masztów węglowych jest powiększanie się otworów wokół nitów okuć metalowych, spowodowane silnymi dynamicznymi przeciążeniami osprzętu (najczęściej o charakterze losowym) - w pracy zaproponowano nieniszczącą metodę określania uszkodzeń masztów (profili) kompozytowych metodami wibroakustycznymi oraz określania właściwych symptomów.

EN

One of the most critical and unseen damage to the carbon masts is an increase in the holes around the securing rivets, caused by strong, dynamic overloads from fixtures most frequently of a random character. There are several methods of determining the state of the holes. A suggestion is given of using a non-destructive method of estimating damages to the composite masts (profiles) based on vibroacoustics and observation of characteristic symptoms.

2

A Power Transformer as a Source of Noise

100%

Zawieska W. M.

International Journal of Occupational Safety and Ergonomics

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2007

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tom Vol. 13, No. 4

381–389

EN

This article presents selected results of analyses and simulations carried out as part of research performed at the Central Institute of Labor Protection – the National Research Institute (CIOP-PIB) in connection with the development of a system for active reduction of noise emitted by high power electricity transformers. This analysis covers the transformer as a source of noise as well as a mathematical description of the phenomenon of radiation of vibroacoustic energy through a transformer enclosure modeled as a vibrating rectangular plate. Also described is an acoustic model of the transformer in the form of an array of loudspeakers.

3

Vibroacoustic analysis of the Polish pharmacy robot Fablox

84%

Łapka W.

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tom Vol. 31, nr 3

art. no. 2020312

EN

This paper describes the vibroacoustic analysis of the Polish pharmacy robots Fablox 1 and 2, as a part of research and development work to build an automated, modular pharmacy robot that meets the requirements of the false directive 2011/62 / EU to counteract the illegal distribution of drugs in the European Union. There were undertaken acoustics and vibration measurements of a pharmacy robot under typical working conditions. Point measurements of a one-third octave spectra of a sound pressure levels and RMS values of acceleration were made at measuring points located in the room and at the pharmacy robot. The acoustic tests were divided according to the location of the measurement points into measurements inside room and noise measurements in the near field of the pharmacy robots. The vibration measurements were made directly on the devices. Based on the analysis of the one-third octave spectra of the noise of the Fablox pharmacy robots, the sound components were determined, which are responsible for achieving high noise levels in room. The acoustic measurements in the near field at a distance of 15 cm from the unloading / front side of the pharmacy robot Fablox 1 and Fablox 2 in room, showed that the arithmetically averaged A-sound level on the measuring surface with closed housing for the movement of the head through all three loading modules is higher for the pharmacy robot Fablox 2 (66.9 dB) by 1.7 dB than the equivalent A-sound level for the Fablox 1 (65.2 dB). Due to the fact that the pharmacy robot is mostly used in the working environment in the pharmacy, the noise it generates has a large impact on employees and customers.

4

Vibroacoustic analysis in the assessment of the technical condition of the aircraft airframe composite elements

67%

Mokrzan D. , Milewicz J. , Szymański G. M. , Szrama S.

Diagnostyka

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2021

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tom Vol. 22, No. 2

11--20

EN

The paper presents the method of assessment of the technical condition of the leading edge of the horizontal stabilizer of an F-16 Block C aircraft made from composite materials. The described method was an experimental measurement of the acoustic pressures generated by the technically operational element and the element with the distorted structural continuity and then a comparison of these pressures in the curves of time and frequency in order to assess how the damage impacts the parameters of the acoustic wave. The test was performed in a dual-channel system, the pressure was induced through impacts on the investigated element with an impact hammer and then, based on the measured induction parameters and the generated acoustic wave, the function of frequency response was calculated, based on which the authors assessed how the structural damage influenced the curve characteristics of the acoustic pressure in the domain of frequency. The described method may be used as an efficient method of non-destructive diagnostics of the airframe elements of an aircraft.

PL

Artykuł przedstawia metodę oceny stanu technicznego krawędzi natarcia statecznika poziomego statku powietrznego F-16 Block C wykonanej z materiałów kompozytowych. Opisywaną metodę stanowił eksperymentalny pomiar ciśnienia akustycznego emitowanego przez element sprawny technicznie oraz element z naruszoną ciągłością struktury, a następnie porównanie ich przebiegu w domenie czasu oraz częstotliwości celem ustalenia w jaki sposób uszkodzenia wpływają na parametry emitowanej fali akustycznej. Badanie dokonywane było dwukanałowo, ciśnienie akustyczne wzbudzane było za pomocą uderzeń w badany element za pomocą młotka modalnego, następnie na podstawie zmierzonych parametrów wzbudzania oraz wywołanego nim fali akustycznej obliczono funkcję odpowiedzi częstotliwości, na podstawie której określono jak uszkodzenie struktury wpływa na przebieg charakterystyki ciśnienia akustycznego w dziedzinie częstotliwości. Opisywana metoda może służyć za skuteczną metodę diagnostyki nieniszczącej elementów płatowca statku powietrznego.