Wave displacement of rigid bodies and particles

The displacement of various particles and mechanical systems by waves finds wide use in technical devices, technological processes, takes place in non living and living nature. Here the system displaced by waves with four degrees of freedom is analyzed when one member of the system, while contacting with the working profile of the input member performing wave motion, provides motion to the output system.The obtained differential equations of motion of the system have been analyzed analytically and numerically. For the analytical investigation modification of the asymptotic method is used, which is based on the division of motion into the slow and quick motions. This method is justified when the frequencies of variation of slow motions are much smaller than the frequencies of quick motions.When the working surface of the input member moves according to the harmonic Rayleigh waves more detailed full investigations have been performed. The characteristics of transition to steady state and of stationary regimes of motions have been obtained, such as the conditions of existence and stability of the stationary regimes, curves of bifurcation, existing complicated motions

Some problems of nonlinear precise vibromechanics and vibroengineering (summary)

The investigations of the author in the field of precise vibromechanics and vibroengineering are overviewed. Some effects and qualities of nonlinear systems as well as developments of new principles of operation thereof are considered. Various designs of mechanical systems of different types, new principles, innovations and more than 1750 inventions and patents have been developed with co-authors

Problems of precise vibromechanics and vibroengineering

A review on investigations of precise vibromechanics and vibroengineering performed in Lithuania is presented in this paper. Results of research, inventions and innovations obtained in this field are discussed. Some of the development in the area of precise vibromechanics are presented in more details

Research of synchronization of pneumatic vibroexciters operating on air-cushion with feeding pulsatile pressure

A synchronization method of pneumatic actuators operating in autovibration mode and fed by pulsatile pressure has been investigated. A mathematical model was analysed numerically describing the dynamics of two vibroexciters connected through aerodynamic channel. The effect of parameters of pulsatile feed pressure on shapes of vibrations of vibroexciter’s working body has been determined. Values of geometrical and dynamical parameters at which synchronization of the mechanical system takes place have been determined. In this case, actuator’s movement law can be both harmonic and non-harmonic in case of pulsating amplitude

Dynamic study of transportation containers with packages

The paper studies the motion of transportation machine with packages on uneven road. Conditions of transportation that reduce the influence of harmful vibrations to the packages are determined. For this purpose the region was established where the slippage of packages with respect to the transported box of packages does not occur. The conditions for location of eigenfrequencies and forced frequencies are determined with the purpose to ensure that the system operates far from resonances. In order to avoid large overloads it is recommended to choose the velocity of motion in such a way, that the difference between the eigenfrequencies and the forced frequencies would be maxmin

Piezoelectric actuators and their application in precise-positioning systems and space structures

Complex piezoelectric actuators are frequently used in mechanisms of optical systems. They can be bimorph, axial and complex- combined stacks. This paper deals with axial piezostacks used in piezoconverters. They make it possible to develop and unipolar or bipolar motion which ensures the displacement dependent on each piezoelement of the compound stack section. The bifurcation problem of a piezodrive has been solved by evaluating physical properties of piezoelements in piezostacs and sealing material. It has made it possible to prove that piezostacs have a lot of static operation possibilities. The original solution of the actuator enabled the choice of optimal initial stresses in piezostacs. The experimental investigation of piezodrives with combined piezostacs have revealed the possibilities to optimize the design and materials for obtaining maximum displacement. These piezoelectric actuators may be applied in various systems like gyroscopes, telescopes

Cleaning of the surface contaminated by micro-particles by means of vibrations

This article is about vibration technologies adaptation for polluted surface cleaning. This cleaning method can be adapted in various areas [1-3]. For example, for used automotive air filters cleaning or during operation prolonging their life. Also this method can be used in buildings, because if in house is installed recuperator it is necessary to use air filters. During the exploitation this filters became polluted by contaminant particles. That to increase air filtering quality and prolonging filter life may be used vibration technologies

Vibrations of the nonlinear system in which stationary harmonic excited multivalued regimes in the vicinities of resonances do not exist

A nonlinear dynamical system is investigated which consists from a mass between two linear elastic connecting elements with different coefficients of stiffness. Laws of vibrations and characteristics of eigenvibrations of the system as well as of self-decaying vibrations of the system with damping and of the system with harmonic excitation are determined. Dynamical qualities of the system are revealed. It is shown that the system has infinite number of eigenfrequencies and that in the resonance zones multivalued stable and unstable motions do not exist in the systemKauno technologijos universitetasSistemų analizės katedraVytauto Didžiojo universiteta

Forced vibrations of vibro impact system with zero tightening with harmonic resonant excitation

An important problem for engineering practical applications is investigated: namely dynamics of the system by taking into account dissipative forces and with an aim that those steady state vibrations should be stable and single valued. This is achieved by choosing suitable parameters of the investigated system. Forced vibrations of vibro impact system with zero tightening with harmonic resonant excitation are investigated. Results for various typical parameters of the analysed system are presented. Dependence of characteristics of motion in steady state regime from the main parameters of the investigated system is investigated. The obtained results are useful in the process of design of vibro impact systems for use in technologies and machines of corresponding typeKauno technologijos universitetasSistemų analizės katedraVytauto Didžiojo universiteta

Vibroimpact mechanism in one separate case

It is known that in the vibroimpact system at the chosen values of parameters linear relationship between impact velocities and eigenfrequencies may exist. The purpose of this paper is to reveal the qualities of the systems of this type. Investigations are performed by analytical and numerical methods. It is determined that in the systems of this type nonlinear solutions with infinite series of harmonics exist. Multivalued stable and unstable regimes do not exist in the systems. The obtained analytical relationships enabled to reveal new qualities of the systems and to make useful conclusionsKauno technologijos universitetasSistemų analizės katedraVytauto Didžiojo universiteta