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1

Reverse task of passive and active mechanical system in torsional vibrations

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 35, nr 2

129-137

EN

Purpose: The main aim of this paper is to develop a method for finding structure and parameters, i.e. a structural and parameter synthesis, of an active model of a viscous damper mechanical system in vibrations. The aim is to perfect the synthesis seen as modification at the sub-assembly design level in relation to the required spectrum of vibration frequency of the system. Design/methodology/approach: With complex systems classic design is very time consuming and it does not always produce satisfactory results. Therefore, it is necessary to use other design methods, such as the inverse task, which is called synthesis. It is searching for a system structure, together with elements value, which realizes the required frequency characteristics. Findings: Using the active elements allows complete elimination of the oscillations. The conducted analysis show that it is not necessary to use both the active and passive elements, as using only active elements produces the same results. Research limitations/implications: The scope of discussion is reverse task of mechanical system in torsional vibrations including passive and active elements, but for this type of systems, such approach is sufficient. Practical implications: The methods of reverse task and analysis can be base of design and construct for this type of mechanic systems. Originality/value: Thank to the approach, introduced in this paper, 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 with elements reducing vibrations.

2

Synthesis of mechanical systems including passive or active elements

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 26, nr 1

18-25

EN

Purpose: In this paper there are presented basic methods of synthesis of mechanical systems including active and passive elements. The major aim of the research is to work out a method of structure and parameters searching i.e. structural and parametric synthesis of a discrete model of mechanical system on the base of desired requirements. The requirements pertain to dynamic features of the system, particularly its frequency spectrum. The purpose of this paper is also comparison of reduction of vibrations of mechanical systems by use the passive or active elements. Design/methodology/approach: In this article was used unclassical method of polar graphs and their relationship with the algebra of structural numbers. This method enables analysis without limitations depending on kind and number of elements of complex mechanical system using electronic calculation technique. Findings: Use of active elements into the elimination of vibration offers the possibility to overcome the limitations of the methods of passive elimination of vibration, such as, in particular, low efficiency in case of low-frequency vibration. Research limitations/implications: The scope of discussion is synthesis of passive and active mechanical systems, but for this type of systems, such approach is sufficient. Practical implications: The results represented this work in form of polar graphs extend the tasks of synthesis to other spheres of science e.g. electric systems. 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 use an unclassic method of polar graphs and their relationship with the algebra of structural numbers, can be possible correcting systems as early as during the designing of future functions of the system as well as during the construction of the system.

3

Polar graphs and structural numbers in synthesis of active and passive mechanical systems

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 30, nr 1

43-50

EN

Purpose: The main purpose of this work is the presentation analysis and synthesis of mechanical systems including passive and active elements reducing 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. The aim of this paper is also comparison of these two methods of reduction of vibrations. Design/methodology/approach: In this paper was used method of polar graphs and their relationship with algebra of structural numbers. This method is called a non-classical method. 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: The application of active elements to eliminate vibration enables overcoming limitations which occur if passive elements are used. Active elements give better results in case of reduction of low frequency vibrations. Presented approach simplifies the process of selecting the dynamical parameters of systems in view of their dynamical characteristics. Research limitations/implications: The scope of discussion is analysis and synthesis of mechanical systems including passive and active elements reducing of vibrations, 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, introduced in this paper, 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 with elements reducing vibrations.

4

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.

5

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.

6

Synthesis of mechanical systems including passive or active elements reducing of vibrations

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

323-326

EN

Purpose: In this work there is presented basic method of synthesis of active and passive mechanical systems realization. The principal aim of the research is to work out a method of structure and parameters searching i.e. structural and parametric synthesis of a discrete model of mechanical system on the base of desired requirements. The requirements refer to dynamic features of the system, particularly its frequency spectrum. The purpose of this paper is also comparison of reduction of vibrations in mechanical systems by use the passive and active elements. Design/methodology/approach: In this work used unclassical method of polar graphs and their relationship with algebra of structural numbers. This method enables analysis without limitations depending on kind and number of elements of complex mechanical system using electronic calculation technique. Findings: Use of active elements into the elimination of vibration offers the possibility to overcome the limitations of the methods of passive elimination of vibration, such as, in particular, low efficiency in case of low-frequency vibration. Practical implications: The results represented this work in form of polar graphs extend the tasks of synthesis to other spheres of science e.g. electric systems. 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, an unclassical method of polar graphs and their relationship with the 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.

7

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.

8

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.

9

Comparison of methods of reduction of vibrations

Białas K.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 1

87-94

EN

Purpose: In this work there are presented basic methods of reverse task of active and passive mechanical systems realization. The principal aim of the research taken is to work out a method of structure and parameters searching i.e. structural and parametric synthesis of discrete model of mechanical system on the base of desired requirements. The requirements refer to dynamic features of the system, particularly their frequency spectrum. Purpose of work is also comparison of active and passive method reduction of vibrations. Design/methodology/approach: In this work used unclassical method of polar graphs and their relationship with algebra of structural numbers. This method enables analysis without limitations depending on kind and number of elements of complex mechanical system using electronic calculation technique. Using method makes also possible designing systems including active or passive elements reducing of vibrations. Findings: Introduced in this paper approach adopted makes it possible to undertake actions aiming at the elimination of phenomena resulting in the unwanted operation of machinery or generation of hazardous situations in the machinery environment. Practical implications: The results represented this work in form of polar graphs extend the tasks of synthesis to other spheres of science e.g. electric systems. 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.

10

Liczby strukturalne w analizie aktywnych układów mechanicznych

Buchacz A., Żurek K.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2003

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z. 20

52-56

PL

W pracy przedstawiono modelowanie i analizę aktywnych układów mechanicznych za pomocą liczb strukturalnych. Celem przeprowadzenia takiego modelowania jest poznanie i udoskonalenie opisu i metod projektowania tak aby formalizm matematyczny w pełni ujmował istotę problemu jaki stanowi wyznaczenie charakterystyki tych układów. Przedstawiony model umożliwia również jednoznaczne rozwiązanie zadania odwrotnego, czyli syntezy.

EN

Modelling and analysis of active material systems by means of structural numbers has been shown in the thesis. The aim of such modelling is studying and improvement of the description and methods of designing so as the mathematical formalism fully explained the essence of the problem which means determination of the systems characteristic. The model shown enables as well the unique solution of the converse task i.e. synthesis.

11

Analiza aktywnych układów mechanicznych za pomocą grafów biegunowych i liczb strukturalnych

Buchacz A., Żurek K.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2002

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nr 18

51-62

PL

W pracy przedstawiono modelowanie oraz analizę aktywnych układów mechanicznych za pomocą metody grafów i liczb strukturalnych. Celem przeprowadzenia takiego modelowania jest poznanie i udoskonalenie opisu i metod projektowania tak aby formalizm matematyczny w pełni ujmował istotę problemu jaki stanowi wyznaczenie charakterystyki tych układów. Przedstawiony model umożliwia również jednoznaczne rozwiązanie zadania odwrotnego, czyli syntezy.

EN

Modelling and analysis of active materiał systems by means of graph method and structural numbers has been shown in the thesis. The aim of such modelling is studying and improvement of the description and methods of designing so as the mathematical formalism fully explained the essence of the problem which means determination of the systems characteristic. The model shown enables as well the uniquesolutionoftheconversetask i.e. synthesis.

12

Active material systems modelling by means of graphs as introduction to their analysis by means of structural numbers

Buchacz A., Żurek K.

Vibrations in Physical Systems

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2002

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Vol. 20

118--119

13

Modeling arbitraty sets of combintorial objects and their sequential and parallel generation

Kapralski A.

Studia Informatica

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2000

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Vol. 21, nr 2

1-193

EN

We give the representations of different subsets of compositions, decompositions, number and set partitions by means of choice functions of indexed families. The structure of the symmetric sets of choice functions is represented by investigated tables D related to Pascal's triangle and to the Stirling's numbers. Unranking and ranking representation models concerning sets of choice functions are developed. We study transformations of the models their equivalence, congruence and isomorphism basing on the tables D. We have shown superiority of the investigated models for representing the sets of combinatorial objects in comparing with the classical methodology. Then, the basic algorithms and their variants for different classes of models concerning the generation of choice functions are developed. The algorithms concerning rank use widely the tables D. The general methodology for parallel or distributed generation of the choice functions in SIMD or MIMD systems is used and developed.

PL

Zaproponowano metodę reprezentowania arbitralnych podzbiorów kompozycji liczb, dekompozycji zbiorów, podziałów liczb i zbiorów poprzez odpowiadające zbiory funkcji wyboru rodzin indeksowych. Istotne znaczenie dla reprezentowania arbitralnych zbiorów obiektów kombinatorycznych mają rosnące funkcje wyboru, monotoniczne funkcje wyboru oraz bijekcje. Zaproponowano i rozwinięto modele zbiorów obiektów kombinatorycznych jako modele nierankingowe oraz modele rankingowe. Przedstawiono ogólną teorię struktury arbitralnych zbiorów funkcji wyboru. Struktura ta reprezentowana jest poprzez tablice D, których elementy pozostają w związku z trójkątem Pascal'a oraz liczbami Stirling'a. Tablice D są wykorzystywane ponadto w algorytmach tworzących podstawy systemu generowania obiektów kombinatorycznych. Przedstawione w dalszej części twierdzenie o rankingu precyzuje własności modeli optymalnych z punktu widzenia możliwie najbardziej zwartych zbiorów rankingów funkcji należących do modelowanych zbiorów. Uzyskanie możliwie najbardziej zwartego zbioru rankingów ma istotne znaczenie dla sekwencyjnego, rozproszonego i równoległego generowania zbiorów funkcji wyboru. Ogólna metodologia generacji zbiorów funkcji wyboru w systemach SIMD, MIMD jest przedstawiona i rozwinięta w kolejnych rozdziałach.