Wyniki wyszukiwania - BazTech

1

Static optimisation of mechanical systems based on the method of extremal regulation

Homišin Jaroslav

Zeszyty Naukowe. Transport / Politechnika Śląska

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2019

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z. 103

12--29

EN

A change in torsional stiffness of pneumatic tuners can be achieved by changing the pressure of the gaseous medium in the course of the mechanical systems' operation or while idle. Based on this statement, we tuned mechanical systems with torsional vibration when they are either idle or when they reach stable condition during operation. The principle of tuning mechanical systems with torsional vibration during operation when their condition is stable lies in the appropriate adaptation of basic dynamic properties (dynamic torsional stiffness and damping factor) of the pneumatic tuner to the dynamics of the system. This was achieved with a control system that helps create a closed control feedback loop. In this way, we can continuously change, that is, adapt the dynamic properties of the pneumatic tuner to the dynamics of the mechanical system so that no dangerous torsional vibrations occur while the system is in operation mode.

2

FEM applications to model friction processes in plastic strain conditions

Lenik K., Korga S.

Archives of Materials Science and Engineering

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2010

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Vol. 41, nr 2

121-124

EN

Purpose: The analysis of FEM applications to evaluate stress states in investigated tribologic processes of plastic working in a special tribological device designed for the purpose of this research. Design/methodology/approach: The analysis and modeling of upsetting processes in movement conditions by means of FEM. Findings: The paper presents the application of FEM and its methodology of computations for the established friction conditions in real conditions and in virtual conditions. The common properties and differing ones for both methods have been described. Research limitations/implications: The research on the carried upsetting process in movement conditions makes possible to determine the effectiveness of applied methodology of investigation. Practical implications: Finite Element Method can be successfully used as a tool to examine plastic strain phenomena at considerations of different working conditions of particular elements. Originality/value: The use of a special instrument for friction tests and of FEM to evaluate friction processes in plastic strain conditions.

3

Graphs and structural numbers in analysis and synthesis of mechanical systems

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 29, nr 2

151-154

EN

Purpose: The main purpose of this work is the introduction the algorithm of a analysis and synthesis of mechanical systems. The systems containing passive and active elements reducing of vibrations. In result of conducted synthesis was received structures and parameters of a discrete model meeting the defined requirements concerning the dynamic features of the system, in particular, the frequency spectrum. Design/methodology/approach: In this paper was used a non-classical method of polar graphs and their relationship with algebra of structural numbers. The use of such a method enables the analysis and synthesis of mechanical systems irrespective of the type and number of the elements of such a system. Findings: Presented approach simplifies the process of selecting the dynamical parameters of systems in view of their dynamical characteristics. The application of active elements to eliminate vibration enables overcoming limitations which occur if passive elements are used. Research limitations/implications: The scope of discussion is analysis and synthesis of passive and active mechanical systems, but for this type of systems, such approach is sufficient. Practical implications: The practical realization of the analysis and synthesis introduced in this work can find uses in designing of machines with active and passive elements with the required frequency spectrum. Originality/value: Thank to the approach, introduced in this work, can be conducted as early as during the designing of future functions of the system as well as during the construction of the system. Using method and obtained results can be value for designers of mechanical systems.

4

Reverse task of passive and active mechanical systems

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 2

51-54

EN

Purpose: The main purpose of this work is to present the algorithm of a converse problem of dynamics of mechanical systems containing passive and active elements. Solving the problem results in obtaining structures and parameters of a discrete model meeting the defined requirements concerning the dynamic features of the system, in particular, the frequency spectrum. Another objective of this work is to compare the reduction of vibration by means of passive or active elements or while using passive and active elements at the same time. Design/methodology/approach: The work involves the application of a non-classical method of polar graphs and their relation to structural algebra. The use of such a method enables the analysis of mechanical systems irrespective of the type and number of the elements of such a system. Findings: The application of active elements to eliminate vibration enables overcoming limitations which occur if passive elements are used. One of the most important limitations is low efficiency in case of low-frequency vibration and inability to reduce vibration of selected parts of the system. Research limitations/implications: The scope of discussion is reverse task of passive and active mechanical systems, but for this type of systems, such approach is sufficient. Practical implications: The practical realization of the reverse task of dynamics introduced in this work can find uses in designing of machines with active and passive elements with the required frequency spectrum. Originality/value: Thank to the approach, unclassical method of polar graphs and their relationship with algebra of structural numbers, can be conducted as early as during the designing of future functions of the system as well as during the construction of the system. Using method and obtained results can be value for designers of mechanical systems.

5

Metoda diagnostyki energetycznej w zastosowaniu do rozpoznawania stanu technicznego i obciążenia belek

Dobry M.

Diagnostyka

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2005

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Vol. 36

39--44

PL

W pracy przedstawiono nową metodę diagnostyki energetycznej. Metoda umożliwia rozpoznawanie stanu technicznego i obciążenia belki na podstawie analizy mocy sił wewnętrznych belki pobudzonej do drgań siłą impulsową. Wstępne badania wykazały również, że stosując tę metodę, możliwe jest rozróżnianie historii obciążenia belki.

EN

New energy diagnostics method has been presented in the paper. The method allows recognition of technical condition and load of the reinforced concrete beam, based on power analysis of the internal forces in the beam excited to vibration using impact force. Preliminary investigations also show, that it is possible to determine history of the beam loading, by applying this method.

6

Application of the “Mathematica” System to Solving Small Vibration Problem of the Multi Degree of Freedom Mechanical Systems

Drzewiecki A., Starosta R., Kołat P.

Vibrations in Physical Systems

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2004

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Vol. 21

143--146

7

Holistyczne modele procesów degradacji w systemach mechanicznych - przegląd

Cempel C.

Diagnostyka

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2003

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Vol. 29

7-14

PL

W pracy dokonano przeglądu modelu teorii i zastosowań procesora energii o skończonym potencjale destrukcji. Najważniejszym zastosowaniem wszelkich odmian tego procesora jest możliwość holistycznego modelowania ewolucji i dynamiki części mechanicznej różnego typu systemów, również mechatronicznych. Idea procesora energii jest na tyle płodna i uniwersalna że można wykorzystać ją do modelowania jednomodalnego zużywania się materiału, z jednej strony, a z drugiej do modelowania samopodobnych hierarchicznie zorganizowanych systemów złożonych z możliwością analitycznego badania rozpływu energii.

EN

Mechanical subsystems are key elements of civil and mechanical engineering as well as mechatronic products. Independently of the size of subsystem they may limit the safety and functionality of the main system, so we have to know the long term and short term behavior of mechanical subsystem. The main idea of holistic modeling is illustrated in the paper, and energy processor model can be digested more from some references. But it seems to the author that inference properties of holistic modeling and energy processor models are not widely known and used. Due to its fractal properties, they can be used to model the behavior of the part as well as the whole system, enabling to trace the energy flow, dissipation and wear inside the system.

8

Badania wektorowych pól akustycznych drgających systemów mechanicznych

Weyna S.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2000

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nr 18

433-438

PL

Graficzna wizualizacja (3D) przepływu energii akustycznej w odniesieniu do warunków rzeczywistych pozwala wyjaśnić wiele, dotąd mało teoretycznie poznanych szczegółów (przepływy wirowe, efekty rozproszenia, rozkłady cienia za przegrodami, itp.). Przedstawione wyniki badań natężeniowych pokazują graficznie (wektorowo) przepływy energii akustycznej jako efekty promieniowania akustycznego drgających struktur. Badania eksperymentalne, poprzez ocenę skutków promieniowania w pobliżu drgających struktur, pozwalają znajdować lokalne źródła transportu energii akustycznej (hałasu) do otoczenia.

EN

Graphical presentation (3D) of acoustic energy flow in real acoustic fields can explain many particulars, concerning in the areas for which it is difficult to make theoretical analysis (vortex flow, effects of scattering, shielding, etc). With application of sound intensity techniąue, in the article presents the spatial distribution of acoustic energy flow (vector effect) over the radiated structures. Experimental studies were carried out to examine the wave close to the vibrating structure, looking for the local noise sources, from which the acoustic energy will be transmitted to outside.