Katarzyna Białas

Passive and Active Elements in Reduction of Vibrations of Torsional Systems

The adverse effects of vibrations on the performance of machines and their environment are the subject of various studies. That is why already in the machine design stage the designers have to face the problem of preventing undesirable effects in the functioning of new machines as well as adapting complete machines to the requirements resulting from the current knowledge on hazards caused by these machines. There are a number of methods for preventing excessive vibrations, which have an impact on machine sub-assemblies and elements. In particular, the passive, semi-active and active vibration-reducing systems can be distinguished [4,5].

Electrical Elements in Reduction of Mechanical Vibrations

This work presents methods of reduction of the vibration of mechanical systems by means of active elements as well as examples of implementation of active reduction of vibration by means of electrical elements [. This work also describes a structural and parametric synthesis, which can be defined as the design of systems meeting specific requirements. These requirements refer to the frequency values of the systems vibration. The presented approach i.e. a non-classical synthetic method applied in designing mechanical systems, one (as early as at the design and construction stage) may verify future systems [1-. This work presents the description of vibration reduction methods. The most popular methods are passive, active and semi-active. An important aspect of this work is the presentation of several possibilities of the physical implementation of active subsystems. In examples active subsystems consisted of the following electric elements is coil with a movable core. In this work is presents influence of electrical subsystem to basic mechanical system. Designer should analyse the resultant systems and investigate the interaction between the subsystems and the basic system [4-.

Comparison of active and semi–active damping in synthesis of various mechatronic discrete systems

Presented research highlights possibility of application of additional active absorbers to mechatronic discrete structures for vibration isolation, in relation to requirements in form of poles and zeros. This new function is defined and compared with semi–active configuration of mechatronic systems that can be obtained by LC or LRC control in external electric network with negative capacitance. Basing on selected examples and types of considered displacement models received from synthesis, respective parameters responsible for damping functions have been investigated. Comparing frequency response functions and dynamical flexibilities, active and semiactive vibration isolation methods have been confronted with regards to damping performance.

Passive and Active Vibration Isolation Methods in Discrete Mechatronic Systems

Piezoelectric actuators are more and more common in many different technical and precision industries. Mechatronic systems which combine them with mechanical models and steering recently are used in plenty practical applications. In this paper, discrete mechatronic systems have been compared relating to known passive vibration isolation method and active that has been additionally introduced to considered systems. Requirements for the systems have been given in form of poles and zeros. Basing on amplitude response functions and dynamical flexibilities, damping performance in both cases has been investigated.

The Influence of Changing the Parameters of Electrical Components Implementing the Active Reduction of Vibration

The structural and parametric analysis presented in this work is understood as an inverse task of dynamics. The solution to this task is to obtain structure and parameters of a system meeting initial requirements. This synthesis may be used as a non-classical method of designing mechanical systems [1÷7]. The presented work extends this issue. Apart from designing a system consisting solely of passive elements, it also describes a subsystem, whose operation reduces undesired vibration of the primary system. The basic analysis which will be performed is to test the influence of applying electric elements on the primary mechanical set [1,3,6]. The analysis will be done on the example of system which were obtained while conducting the structural and parametric synthesis. In order to design a system including an active subsystem in the form of electric elements reducing vibration by means of a non-classical method of designing.

Mechanical Subsystem as Implementation of Active Reduction of Vibration

The main objective of this work is to present a reverse task of the dynamics of discrete vibratory mechanical systems. This task is reverse to analysis and is called structural and parametric synthesis. As a result of performing the synthesis one obtains a structure and values of individual parameters of the system of required properties. Such properties refer to the determination of individual frequencies of the system vibration. Synthesis is divided into two stages. The first stage consists in definition of the structure as well as the values of parameters of a passive system without vibration reduction. In the second phase, one selects a method of vibration reduction as well as system structure and parameters with vibration-reducing elements. In case of already-existing systems, the first stage consists in the identification of the system and its analysis. There are no changes in the second stage (Figure 1) [. Another objective of this work is to use mechanical elements in the form of kinematic excitations as the implementation of active reduction of vibration as well as to check the influence of this subsystem on the basic system. The application of the synthesis presented in this work enables the correction of the already-existing machines and devices as well as the modification of newly-created systems with the view of their future functioning.

Vibration Analysis of Mechanical Systems with the Discrete-Continuous Distribution of Parameters

This paper presents an analysis of mechanical systems with the discrete-continuous distribution of parameters performing small vibrations around the adopted state of equilibrium. The modelling and analysis of discretecontinuous vibration systems with conjugations using the non-classical method is a more general approach as compared to modelling and analysis in classical terms. The method presented in this article permits a simplification and facilitates the understanding of mechanical vibrations in such class of systems.

Application of Electric Subsystem as Implementation of Reduction of Mechanical Vibrations

This work presents methods of reduction of the vibration of mechanical systems by means of active elements as well as examples of implementation of active reduction of vibration by means of electrical elements [1], [2]. This work also describes a structural and parametric synthesis, which can be defined as the design of systems meeting specific requirements. These requirements refer to the frequency values of the systems’ vibration. The presented approach i.e. a non-classical synthetic method applied in designing mechanical systems with elements reducing unwanted vibrations. As a result of the synthesis, one can obtain the structure and parameters of the system of required properties. The synthesis may also be applied to modify the already existing systems in order to achieve a desired result [1–3].

Reverse Task of Mechanical System with Active Reduction of Vibration

The main purpose of this work is the presentation reverse task of mechanical systems including active elements. This reserve task is known as synthesis of mechanical system. 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 presented approach i.e. a non-classical synthetic method applied in designing mechanical or mechatronical systems, one (as early as at the design and construction stage) may verify future systems. The aim of this paper is also analysis of obtained system to check relationship between basic system and active subsystem reduction vibrations. This active subsystem was consisted from electric elements. 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. Active elements give better results (in compare with passive elements) 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. Thanks 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.