Mechanics
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ISSN 1734-8927
e-ISSN: 2300-7060
Issue Date
2008
Volume
Vol. 27
Number
No. 4
Description
Journal Volume
Mechanics
Vol. 27 (2008)
Projects
Pages
Articles
Periodic control of the bar with point mass
(Wydawnictwa AGH, 2008) Bieda, Maciej; Piekarski, Zbigniew
The following article discusses the usage of optimization theory with quasi periodic control to form a vibrating bar with point mass that is situated on the bar's axis. The maximum principle was changed and used to calculate a numerical sample. The principle uses the new condition for optimisation containing several constituent hamiltonians. The hamiltonians facilitated the calculation of the quasi periodic controls. The result of the calculation was a numerical sample, which specified how the quasi-periodic cross-section of the bar depends on the mass and the point of the mass position along the bar's axis.
Numerical and experimental investigations of the flow in the radial fan
(Wydawnictwa AGH, 2008) Fortuna, Stanisław; Sobczak, Krzysztof
The radial fan under investigation transfers energy in the form of mechanical work to the air. A three-dimensional flow structure in the rotor was determined on the basis of the computational and experimental data. A comparison of the numerical simulations by means of ANSYS CFX and thermoanemometer measurements of velocity as well as its components was presented. The results of numerical investigations, measurements and balance method were compared in order to determine the compressor performance characteristics.
Self-tuning damping system for cable vibration
(Wydawnictwa AGH, 2008) Orman, Maciej; Snamina, Jacek
The paper presents calculations of the system giving the maximal dissipation of energy by using the self-tuning damper. The damper is applied to reduce vibrations of inclined cable. It is attached near the lower support of cable. In order to calculate the optimal damping coefficient the self-tuning subsystem is introduced. The optimal damping coefficient is calculated taking into account the criterion of maximal energy dissipated by the damper. Results of calculations indicate that the concept of self-tuning damper can be applied to effective damping of cable vibration under various external inputs.
Simulator of intonation errors: a tool for controlling parameters of acoustic signals in auditory tests
(Wydawnictwa AGH, 2008) Pluta, Marek
Intonation is one of the key elements of music performance and music perception, yet, due to a lack of suitable tools research on this subject was scarce. This paper presents a new and original tool developed particularly for a purpose of intonation perception research: the hardware-software simulator of intonation errors. The simulator is a controllable source of acoustic signals with properties similar to real musical signals. The paper discusses needs and possibilities of realistic simulation, as well as design and application of the simulator. Sample results of auditory tests that investigate impact of simulation's realism on intonation perception are presented.
Modeling and simulation of piezoelectric elements - comparison of available methods and tools
(Wydawnictwa AGH, 2008) Staworko, Michał; Uhl, Tadeusz
The paper presents an overview of modeling techniques of piezoelectric elements and a comparison of a software for simulation mechanical and electro-mechanical systems with a piezoelectric transducer. The described models are applied to simulate a two degrees-of-freedom mechanical system with passive damping, a two-layer and multi-layer piezoelectric bimorph. The results of simulations preformed by the use of the presented software packages are being discussed.