Wyniki wyszukiwania - BazTech

1

Modelowanie hybrydowych korpusów obrabiarek

Kosmol J.

Modelowanie Inżynierskie

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2017

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T. 31, nr 62

49--55

PL

W artykule przedstawiono wyniki modelowania metodą elementów skończonych tzw. hybrydowego korpusu obrabiarki. Celem modelowania było wyznaczenie związków pomiędzy strukturą korpusu hybrydowego a takimi wskaźnikami jak: podatność statyczna, wartości własne, podatność dynamiczna, masa korpusu. Dalekosiężnym celem badań było opracowanie procedur, które umożliwiłyby optymalizację hybrydowego korpusu, rozumianą, jako najkorzystniejszą strukturę z punktu widzenia oczekiwanych własności statycznych, dynamicznych i kosztu korpusu. W artykule, pod pojęciem struktury korpusu rozumie się procentowy udział składnika metalowego (żeliwa, stali) i składnika niemetalowego (polimerobetonu). Wykazano, że tak rozumiana struktura istotnie zmienia właściwości statyczne i dynamiczne korpusu obrabiarki, masę i koszt jego wytworzenia.

EN

The paper presents some results of modeling hybrid frames using Finite Element Method. The main goal of the modeling was identification of relationship between the structure of the hybrid frame and such features like static flexibility, natural frequencies, dynamic flexibility, and mass of the body. Far-reaching goal of the modeling was to work-up procedures which make possible optimization of the hybrid frame, i.e. finding the best structure from the point of view of expected exploitation static and dynamic properties and cost. The best structure of hybrid frame is here understood as the best percentage participation of metal (cast iron, steel) and non-metal (polymer concrete) in the weight of the frame. It was shown that application of such hybrid structures of the frames influence static and dynamic properties as well as mass and cost of the machine very much.

2

Application of graphs in the analysis of vibrating 3-dimensional systems

Wojnarowski J.

International Journal of Applied Mechanics and Engineering

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2016

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Vol. 21, no. 3

761--766

EN

Vibrating 3-dimensional mechanical systems are described by hybrid graphs. By dividing the hybrid graph into a tree and associated co-tree it is possible to describe in terms of matrices: across-flow-variables, stiffness and flexibility. The application of the formalism of graphs makes it possible to analyze mechanical systems in terms of dynamic characteristic and trajectory motion of determinate points.

3

Badania symulacyjne sztywności dynamicznej stołu obrotowego z napędem bezpośrednim

Olszewski J.

Mechanik

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2012

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R. 85, nr 1CD

PL

Wykorzystanie silników momentowych do napędu osi obrotowych obrabiarek pozwala na eliminację przekładni z układów napędowych i jednocześnie wielu problemów z nimi związanych. Niestety, istnieją wątpliwości co do tego, jak kształtuje się sztywność tego typu napędów w warunkach zmiennych obciążeń. W artykule przedstawiono rezultaty rozważań teoretycznych i wstępnych badań praktycznych sztywności dynamicznej stołu obrotowego z napędem bezpośrednim. Symulacje przeprowadzano na podstawie modułu transmitancji widmowej przyjętego modelu w środowisku Matlab.

EN

The use of torque motor to drive the rotary axes of machine tools allows for the elimination of gear drive systems and also many of the problems associated with them. Unfortunately, there are doubts as to how to shape the rigidity of such drives in the conditions of variable loads. The article presents the results of theoretical and practical preliminary research dynamic stiffness rotary table with direct drive. Simulations were carried out on the basis of frequency response function of adopted model in Matlab.

4

Active synthesis of multiaxial drive systems using a comparative method

Dzitkowski T., Dymarek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 49, nr 2

275--284

EN

Purpose: of this paper is the problem of stability and vibration reduction in designed drive systems, in which the essential requirement is to meet the desired dynamic properties. Design/methodology/approach: The method of stabilisation and reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback. Findings: Presented approach simplifies the process of selecting the dynamical parameters of machine drive systems in view of their dynamical characteristics. Research limitations/implications: The scope of discussion is the synthesis of machine drive systems as discrete models of torsional vibrations. Such vibrations are more difficult to detect than flexural ones, which are accompanied by noise and vibrations of the adjacent elements (for example, shaft frames). Due to the absence of symptoms, torsional vibrations are particularly dangerous, as they may be unnoticeable until the destruction of subsystems occurs. Practical implications: High durability and reliability of drive systems is associated with proper setting of system parameters - inertial, elastical and damping. Proper setting of these parameters is made possible by applying synthesis techniques. Originality/value: We should emphasize that the considered problem varies from other issues met in classic mechanics or control theory. The research has been undertaken on the basis of topological methods, developed in scholar environment of Gliwice.

5

Badania sztywności dynamicznej właściwej stołu obrotowego NC z napędem bezpośrednim

Olszewski J.

Archiwum Technologii Maszyn i Automatyzacji

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2011

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Vol. 31, nr 4

125--134

PL

W artykule przedstawiono rezultaty rozważań teoretycznych dotyczących sztywności dynamicznej napędu stołu obrotowego z silnikiem momentowym. Wyznaczono zależność, pomiędzy wybranymi parametrami a wartością rozpatrywanej sztywności dynamicznej, jak również określono wytyczne do nastaw regulatorów badanego układu sterowania. W tym celu posłużono się środowiskiem Matlab W dalszej części artykułu opisano wyniki wstępnych badań przeprowadzonych na rzeczywistym obiekcie. Sztywność dynamiczną właściwą wyznaczano metodą testu impulsowego.

EN

This paper presents the results of consideration about dynamic stiffness of rotary table drive with torque motor. The dependence between dynamic stiffness and chosen parameters of drive had been determined and the guidelines about settings of drive controllers had been drawn up. To solve this problem the Matlab environment has been used. In the next part results of exploratory measurement of real object stiffness had been presented. The measurement consisted in impact test carried out.

6

Design and examining sensitivity of machine driving systems with required frequency spectrum

Dziatkowski T., Dymarek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 26, nr 1

49-56

EN

Purpose: The paper describes the method of synthesis and sensitivity analysis of dynamics characteristics applicable for aiding the process of designing of machine driving systems. Design/methodology/approach: In this work used method of polar graphs and their relationship with algebra of structural numbers, easy for programming. Findings: Presented approach simplifies the process of selecting the dynamical parameters of machine drive systems in view of their dynamical characteristics. Research limitations/implications: The scope of discussion is the synthesis and sensitivity of machine drive systems as discrete models of torsional vibrations. Practical implications: High durability and reliability of drive systems is associated with proper setting of system parameters - inertial, elastical and damping. Proper setting of these parameters is made possible by applying synthesis and sensitivity techniques. Originality/value: We should emphasize that the considered problem varies from other issues met in classic mechanics or control theory. The research has been undertaken on the basis of topological methods, developed in scholar environment of Gliwice.

7

Modelling of Dynamic Reactions in Systems of Rotor-Bearings-Supporting Structure Type

Żywica G.

Machine Dynamics Problems

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2007

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Vol. 31, No. 4

99-109

EN

The article discusses methods of modelling reactions in systems of rotor-bearings-supporting structure type. Author's attention was focused most of all on modelling reactions between the supporting structure and the rotor supported on slide bearings. In the article an overview of well known and presently used methods for determining dynamic characteristics of the rotor supporting structure is given. Significant part of the article is devoted to the presentation and discussion of the proposed method of determining supporting structure characteristics in cases when subtle changes of these characteristics, for instance those caused by the presence of certain defects, are to be taken into account. The proposed method of dynamic characteristics determination allows various changes taking place in the structures supporting the rotating machines to be analysed both at the design stage and during their operation. These changes have frequently noticeable influence on the rotor dynamics.

8

Synthesis and sensitivity of machine driving systems

Dzitkowski T., Dymarek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

359-362

EN

Purpose: The paper presents algorithms of synthesis and sensitivity analysis of dynamics characteristics applicable for aiding the process of designing of machine driving systems. The objective of the paper was to develop algorithms for selecting of design features of physical systems so that dynamic characteristics described in the frequency domain might be shaped in the best possible manner. Design/methodology/approach: In this work used method of polar graphs and their relationship with algebra of structural numbers. This research method of mechanical systems allows quickly and exactly calculates the impact of individual factors on his dynamic properties. Findings: Presented approach simplifies the process of selecting the dynamical parameters of machine drive systems in view of their dynamical characteristics. Research limitations/implications: The scope of discussion in the synthesis and sensitivity of machine drive systems as models of torsional vibrations, but for the kind of systems the approach is sufficient. Practical implications: The developed algorithm of shaping of the dynamic characteristics make it possible to formulate the problem of optimization when making use of the objective functions constraints described in the frequency domain. Originality/value: A process of researching the structure of a system, meeting certain conditions, is inverse to the process of analyzing it. In order words, it's a synthesis. We should emphasize that the considered problem varies from other issues met in classic mechanics or control theory. The research has been undertaken on the basis of topological methods, developed in scholar environment of Gliwice, and on the basis of algebraically methods closely related to these topological ones - that is, methods of graphs and structural numbers.