Wyniki wyszukiwania - BazTech

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Metoda identyfikacji procesu niszczenia elementów konstrukcyjnych z wykorzystaniem analizy wibroakustycznej

Rychlik A.

Zeszyty Naukowe / Wyższa Szkoła Oficerska Sił Powietrznych

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2015

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Nr 3

125--136

PL

W artykule przedstawiona została metoda identyfikacji procesu niszczenia przekroju próbki badawczej oraz próba opisu tego zjawiska za pomocą modelu matematycznego z wykorzystaniem równań Lagrang’a. Proces destrukcji przekroju próbek badawczych realizowany był przez siłę bezwładności obiektu konstrukcyjnego. W opracowaniu zamieszczone zostały wyniki symulacji dla opracowanego modelu matematycznego, a także wyniki pomiarów zgodności modelu z rzeczywistością w oparciu o badania laboratoryjne i eksploatacyjne, na przykładzie elementów przyłączy kontrolno-pomiarowych instalacji rurowych. W oparciu o opracowany model, przeprowadzono analizę wpływu podstawowych parametrów modalnych struktury w postaci współczynnika tłumienia, sprężystości oraz częstotliwości drgań własnych na wielkość energii mechanicznej, generowanej podczas procesu eksploatacji przyłącza manometrycznego.

EN

The article presents the identification method of a specimen cross-section destruction and the attempt to describe this phenomenon with a mathematical model using Lagrange’s equations. The destruction process of specimens was carried out by inertia force of a structural object. The study includes not only the results of a simulation for a developed mathematical model but also those referring to the measurement of compliance between a model and reality based on laboratory and operational tests, with components of control and measurement couplings of piping installations used as examples. Based on a worked out model, the authors carried out the analysis of the impact of basic modal parametres of the structure in the form of a dampening coefficient, elasticity and natural modes on the magnitude of mechanical energy pgenerated during the operation of manometric coupling.

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Kinematic of marine piston-crankshaft system

Murawski L.

Journal of KONES

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2015

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Vol. 22, No. 2

155--162

EN

Two-stroke, slow speed main engines are often installed on merchant ships, because of its very high efficiency. That kind of engine has an output of about 5500 kW per cylinder. The mass of piston-crankshaft system reaches over a dozen tons. That reciprocating masses are source of high level of dynamic inertia forces (mass forces). Those forces have big influence on engines working parameters and characteristics. One of them is instability of crankshaft rotational speed, which leads to dangerous torsional vibrations of propulsion system. Some inconsistency can be observed during analysis of piston-crankshaft system kinematic. In the theoretical engine books, the piston speed and acceleration has only two harmonic components, the inertia forces are depended on engine rotation speed and they doubled rotation speed. However, empirical formulas, published by engines producers, give us at least five harmonic components of mass forces. The author tries to find out the theoretical reason of existing (measured) higher harmonic orders of engines inertia forces. It is a first step for developing monitoring system of propulsion system’s torsional vibrations coupled with axial vibration, dynamic shaft line alignment and crankshaft springing. In the paper two analytical methods of piston displacement, speed and acceleration are presented. Well-known (from literature) equations are compared with more-detailed analytical procedures. The analysis was performed for one of the biggest marine MAN B&W engine, type 7K98MC. A discussion about the analysis results was included in the final part of the paper.

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Nature of Inertia forces

Baurov Yu. A.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 10

14--24

EN

The physical nature of inertia forces is shown on the base of theory of byuons, the theory of “life’ of special unobservable discrete objects – byuons from which the surrounding physical space (dark matter) and the world of elementary particles are formed. The theory of byuons predicts a new non-gauge force of nature which explains of physical nature of inertia forces.