Autor: Vondřich, J. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Machine vibrations with more degrees of freedom
Autorzy:: Vondřich, J.
Thöndel, E.
Powiązania:: https://bibliotekanauki.pl/articles/1429159.pdf
Data publikacji:: 2008
Wydawca:: Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:: Matlab
Simulink
vibration
machine
Opis:: Rigid mounting of machines to a solid base is one of the requirements for high performance and quality of production. Machine vibrations occur as a result of unbalanced revolving masses, loading forces and moments, starting and coasting of driving motors and other effects. We try to eliminate these undesirable vibrations by suitable mounting of the machine and its parts as much as possible. Suitable mounting of the machine is possible using components such as torsion springs, pneumatic springs, rubber pads or other components. The article describes numerical calculation of optimal displacements the machine for the given his parameters.
Źródło:: Journal of Machine Engineering; 2008, 8, 4; 80-87
1895-7595
2391-8071
Pojawia się w:: Journal of Machine Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Optimization of Mounting of a Machine and its Parts
Autorzy:: Vondrich, J.
Havlicek, R.
Powiązania:: https://bibliotekanauki.pl/articles/971107.pdf
Data publikacji:: 2008
Wydawca:: Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:: Matlab
Simulink
air spring
machine
Opis:: Frequency dependence values of input or mutual mechanical impedances of vibrating machines and their parts can be measured using an impedance hammer and a two-channel frequence analyzer. The knowledge of the frequency response of mechanical impedance provides for the determination of properties of vibration energy transmission in the structure of the machine based on which it is possible to adjust the mounting arrangement of the machine and its parts in order to attenuate vibrations. The obtained data concerning the dynamicbehaviour of the machine then serve as a basic for a proper design and implementation of elastic mounting of the machine and its parts on damping elements which attenuate unwanted vibrations to the minimum. The design consists in assembling a model of the machine assuming that elastic mounting has been provided for, describing the model using equations of montion and elaborating their numerical solution. An efficient damping arrangement is achieved by mounting the vibrating parts of the machine using air springs. The air pressure in the air springs can be regulated according to deflections of the individual machine parts measured by accelerometers using a control element. The numeric solution provides for determination of values of stiffness coefficients k and damping coefficient c which would be optimal for the specified machine parameters in order to minimise the defections of the individual machine parts.
Źródło:: Journal of Machine Engineering; 2008, 8, 1; 123-129
1895-7595
2391-8071
Pojawia się w:: Journal of Machine Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Modelling Suppression of Non-Linear Machine Vibration
Autorzy:: Vondrich, J.
Thöndel, E.
Powiązania:: https://bibliotekanauki.pl/articles/971125.pdf
Data publikacji:: 2009
Wydawca:: Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:: Matlab
non-linearity
vibration
machine
Opis:: In this paper, the coupled non-linear differential equations of the model of machine as non-linear dynamical two degree of freedom vibrating system including cubic non-linearity are solved. The system consists of the main system and the absorber. Consider the non-linearity dynamical vibrating system as a model machine, which is compiled of a driven motor, gearbox and mechanisms with elastic and damping parts and driven parts. The absorber is used to control the main system vibrations when subjected to external excitation force. This system represents many applications in machine tools, ultrasonic cutting process, etc. Optimum working conditions for the absorber are by the same frequencies ω = ω2 [1] of the action force F =F0 sinω t and main mass m1. The effects of different parameters of the system are studied numerically with Matlab.
Źródło:: Journal of Machine Engineering; 2009, 9, 2; 45-50
1895-7595
2391-8071
Pojawia się w:: Journal of Machine Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Modelling of vibration with absorber
Autorzy:: Vondřich, J.
Thöndel, E.
Jirku, S.
Powiązania:: https://bibliotekanauki.pl/articles/99605.pdf
Data publikacji:: 2010
Wydawca:: Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:: numerical modelling
Simulink
vibration
machine
absorber
Opis:: Machine vibration occurs as a result of unbalanced revolving masses, loading forces and moments, starting and coasting of driving motors and other effects. We try to eliminate these undesirable vibrations by suitable mounting of the mechanical system. Another possibility of suppression of the vibration machine is to use an absorber. A model of a vibration mechanical system with a vibration absorber is presented in the paper. The model consists of a fixed-end vibrating beam with primary vibrating mass M and with stiffness K and damping B. The harmonic force F with frequency ? and amplitude A acts on the primary mass M as well as on the beam with stiffness k and damping b, where the secondary mass m of the absorber is mounted. The task of the absorber is to minimize the movement of the mass M. A model (Fig. 1) has two degrees of freedom X and x. Two equations describe the movement of the primary mass M and the secondary mass m of the absorber. The model is solved first numerically by using Simulink. In numerical solution it is possible to set up parameters of the mechanical system with respect to the vibration reduction. According to the mechanical requirements for the mechanical system (output trajectory, velocity, forces and torques acting on the individual parts of the system), it is also possible to design input parameters (driving torques and other parameters of the mechanical system). A experimental model will be designed in order to verify results, where a voice-coil will be used as the actuator of the force F Numerical and experimental model allows changing parameters i.e. masses M and m, length L and l of the beams and frequency ? of the excitation force F. The results from the numerical solution are then possible to compare with the measured values of the experimental model. It is assumed that the experimental model will be equipped with accelerometers enabling the measuring of vibration, which will be placed on the masses M and m.
Źródło:: Journal of Machine Engineering; 2010, 10, 4; 100-105
1895-7595
2391-8071
Pojawia się w:: Journal of Machine Engineering
Dostawca treści:: Biblioteka Nauki

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