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Wykorzystanie funkcji działania w diagnostyce prostych obrotowych układów mechanicznych

Marszałkowski Konrad

Journal of Polish CIMEEAC

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2022

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Vol. 17, no 1

66--73

PL

W artykule przedstawiono możliwość wykorzystania funkcji działania w ujęciu praktycznym. W tym celu przeprowadzono eksperyment czynny, w którym przeprowadzono szereg prób zmęczeniowych wału napędowego prostego układu mechanicznego, pracującego w warunkach utraty współosiowości. Zastosowana funkcja działania wartościuje generowane dodatkowe procesy towarzyszące obracaniu się wału. Są to tak zwane procesy resztkowe, które ujawniają się w postaci: drgań mechanicznych, wydzielania ciepła i emisji fal sprężystych generowanych w materiale konstrukcyjnym. Rezultatem badań jest opracowany model diagnostyczny trwałości wału napędowego z wykorzystaniem funkcji działania.

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Energy analysis of the propulsion shaft fatigue process in a rotating mechanical system. Part II. Identification studies – developing the fatigue durability model of a drive shaft

Korczewski Zbigniew, Marszałkowski Konrad

Polish Maritime Research

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2020

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nr 2

120--124

EN

The article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means of an active experiment, that changes in propeller shaft deflection are reflected in the amount of dissipated kinetic energy of masses in rotational motion and the accumulated internal energy in its construction material. Adoption of a high-cycle fatigue syndrome, consisting of diagnostic symptoms determined from the action of the propeller shaft associated with the transformation of mechanical energy into work and heat, as well as with the generation of mechanical vibrations and elastic waves of acoustic emission, is proposed. To assess the diagnostic information quantity brought about by the defined features of propeller shaft fatigue, an experimental research program was developed and implemented, in which two statistical hypotheses are verified: the significance of the impact of the values enforcing the fatigue process, presented in the first part of the article, and the adequacy of the regression equation describing the fatigue durability of the propeller shaft in the energy aspect, constituting the second part of the article. This finally gives us the opportunity, after the appropriate translation of the model test results into full-sized real objects, to develop a methodology to diagnose marine propeller shaft fatigue in operating conditions. The third part of the article is devoted to this issue

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Energy analysis of propulsion shaft fatigue process in rotating mechanical system Part I Testing significance of influence of shaft material fatigue excitation parameters

Korczewski Z., Marszałkowski K.

Polish Maritime Research

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2018

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S 1

211--217

EN

The article discusses the problem of mathematical modelling of energy conversion processes in a rotating mechanical system for the purpose of identifying fatigue states of propulsion shafts in this system. A simplified physical model of the analysed system, constructed in an appropriate scale, has made the basis for the experimental research. The research programme took into consideration mechanical fatigue excitation of the model propulsion shaft to find the correlation between the dynamic system load generated by a bending moment and the energy state of a specified shaft segment. A physical model of the analysed process was proposed, for which the plan of static randomised block experiment was worked out. The recorded experimental results were used for statistical analysis of the significance of influence of the quantities exciting the propeller shaft fatigue process and the adequacy of the developed mathematical model describing shaft’s durability. The analysis made use of the F-Snedecor test. The article describes the general concept of the research, the constructed laboratory test rig, and the methodology of statistical inference concerning the significance of influence of input (exciting) parameters of the physical model on the recorded output parameters. The results of the performed statistical tests confirm the absence of the significance of influence of the rotational speed of the propulsion shaft on the selected types of rotating operation of the mechanical system. As a consequence, only one exciting parameter, which is the loading mass, is going to be taken into account in the functional description of fatigue life of the propulsion shaft.

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Physical model of energy-related processes in a rotating mechanical system for the purposes of diagnosis of the transmission shafts

Korczewski Z., Marszałkowski K.

Journal of Polish CIMEEAC

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2016

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Vol. 11, no 1

69--76

EN

In the present article, selected problems connected with identification of slowly changing energy-related processes accompanying high cyclic fatigue of construction materials of simple mechanical systems, with special consideration of transmission shafts, are mentioned for diagnostic purposes. The article also presents physical models of object and processes that in a simplified way reflect mechanical energy transmission from transmission engine to ship propeller.