Mechanics and Control
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ISSN 2083-6759
e-ISSN: 2300-7079
Issue Date
2014
Volume
Vol. 33
Number
No. 2
Description
Journal Volume
Mechanics and Control
Vol. 33 (2014)
Projects
Pages
Articles
Conditioning electronics in a self-powered vibration reduction system: experimental testing
(2014) Jastrzębski, Łukasz
This paper summarises the results of laboratory testing of a vibration reduction system with energy harvesting capability, implemented in an 2-dof mechanical application. The vibration reduction system comprises of a commercially available RD-1005-3 type magnetorheological (MR) damper and an electromagnetic energy transducer (EPE) executing the reciprocating motion. The aim of the experiment was to compare the performance of the vibration reduction with two types of power conditioning systems and that in which the MR damper coil is fed directly with energy generated by EPE. Frequency characteristics are provided showing the plots of transmissibility coefficients, MR damper force, voltage generated by EPE, current intensity in the MR damper control coil, supplied electric power and mechanical power dissipated by the damper.
Finite element analysis of adhesive bonds using the cohesive zone modeling method
(2014) Korta, Jakub; Młyniec, Andrzej; Zdziebko, Paweł; Uhl, Tadeusz
This paper covers the subject of FE modeling of adhesive joints, which is gaining more and more attention in contemporary industry, especially in the aerospace and automotive sectors. This technique of creating structural connections possesses many advantages over mechanical or welding methods and it seems that it will be exploited extensively in the future mechanical design. The ability of joining dissimilar materials decreased minimum member cross-section size and corrosion inertness can be considered as its most important features. However, in the era of virtual prototyping, it is necessary to conduct reliable computer-assisted analyses of these types of joints. It is because most of the contemporary structures are developed as numerical models first, and only the final pro duct is prototyped physically, to validate the simulation results. The aim of this paper is to demonstrate how to elaborate reliable and accurate adhesive joint models, using a cohesive zone modeling (CZM) method in conjunction with shell-based models. The major profitable consequence of using this modeling technique is that it results in a relatively small number of spatial degrees of freedom, therefore allows for short computational times.
Study of flow-induced vibration phenomena in automotive shock absorbers
(2014) Sikora, Marian
The purpose of this study was to develop a model of the dynamic behavior of a hydraulic vehicle double-tube shock absorber. The model accounts for the effects of compressibility, valve stiction, inertia, etc. and can be suitable for use in the analysis on flow-induced pressure fluctuations in the device. The author highlights all major variables to influence the output of the shock absorber, and then proceeds by performing a series of simulations using the developed model. The model is demonstrated to operate well in the large amplitude and low frequency range as well as the small amplitude and high frequency excitation operation regimes. The results are presented in the form of time histories of pressures in each fluid volume of the damper, flow rates through the valves, piston rod acceleration and force. Fast Fourier Transform (FFT) graphs are presented, too, in order to identify the major components of the pressure fluctuation phenomena in the frequency domain.