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1

Torsional shear device for testing the dynamic properties of recycled material

Gabryś K., Sas W., Soból E., Głuchowski A.

Studia Geotechnica et Mechanica

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2016

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Vol. 38, nr 4

15--24

EN

From the viewpoint of environmental preservation and effective utilization of resources, it is beneficial and necessary to reuse wastes, for example, concrete, as the recycled aggregates for new materials. In this work, the dynamic behavior of such aggregates under low frequency torsional loading is studied. Results show that the properties of such artificial soils match with those reported in the literature for specific natural soils.

2

Analysis of an experimental setup for structural damping identification

Hentschel O. P., Bonhage M., Panning-von Scheidt L., Wallaschek J., Denk M., Masserey P.- A.

Journal of Theoretical and Applied Mechanics

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2016

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Vol. 54 nr 1

27--39

EN

In the present paper, an experimental setup for structural damping determination arising from energy dissipations within the material is presented. The experimental setup is developed in such a way that all unintended damping sources are eliminated. In this connection, priority is also given to the reproducibility of the experimental data. In addition, a vacuum chamber is developed to reduce the damping arising from the interaction with the surrounding medium. Furthermore, beam-shaped specimens are clamped in a suspended way, using screws with an apex to fix the specimens in their nodes of vibration. Then, the influence of test rig specific parameters on the damping value is analyzed. In this context, an ideal setup of the test rig is identified to measure structural damping values arising from dissipations within the material. Finally, a common model for material damping description is parameterized using the experimental data.

3

Influence of Material Damping on Dynamics of Slider-Crank Mechanism

Hać M.

Machine Dynamics Research

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2012

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Vol. 36, No. 2

16-25

EN

In this paper the dynamic analysis of a slider-crank mechanism is presented. It is taken into account the flexibility of links by applying finite element method with beam-type planar finite elements. The influence of material damping on dynamic behaviour of slider- crank mechanism is investigated. Mechanism is driven by variant torque applied to the crank and vibrational transient response is analysed. The midpoint deflection of the connecting rod as well as the displacement and velocity of slider are shown for the cases when Rayleigh proportional damping model is taken into account and for undamped vibration of links.

4

Dynamic effects of material damping in active laminates reinforced with piezoceramic fibers

Pietrzakowski M.

Engineering Transactions

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2006

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Vol. 54, iss. 3

223-231

EN

In the paper rectangular, simply supported, laminated plates composed of classical fiber-reinforced layers and active layers of piezoelectric properties are under consideration. The aim of the study is to determine the influence of anisotropic passive damping on the active vibration reduction achieved and the sensitivity of the system to material axes' orientation of piezocomposite actuator layers. The effects of piezoceramic fiber direction and passive damping intensity are illustrated by means of the amplitude-frequency characteristics.

5

Dynamiczny pomiar własności lepko-sprężystych taśm.

Sokołowska R., Majewski T.

Pomiary Automatyka Kontrola

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2003

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R. 49, nr 6

19-23

PL

Określono wielkości charektryzujące zachowanie się materiałów lepkosprężystych w warunkach obciążeń dynamicznych. Posługując się modelem Kelvina-Voigta, zaproponowano sposób wyznaczenia metodą dynamiczną, zespolonego modułu sprężystości podłużnej. Przedstawiono stanowisko pomiarowe do wyznaczenia własności lepkosprężystych taśm poliestrowych.

EN

The parametres describing the viscoelastic properties of tapes and fibres were defined for dynmic loading. The method of measuring these properties was proposed and a laboratory test stand was built. A series of experiments was carried out which used a model of Kelvin-Voigt in which the complex modulus was defined.

6

Vibration Damping Measurements in Piezoelectric Crystals by Surface Acoustic Waves

Filipiak J., Zubko K.

Molecular and Quantum Acoustics

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2001

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Vol. 22

69-75

EN

To model anisotropic crystals under the circumstances of dynamic force the numerical methods are used. However it is not allowed to compare in a simple way the usability of various materials to the sensors construction where the usable parameters are defined. It is possible when using the models, which describe the dynamic fo the work through evident dependencies of material and construcional parameters. The method of defining the piezoelectric crystal damping and results for ST quartz will be shown in the work. Surface Acoustic Waves (SAW) has been used as a measurement device.

7

Approaches to the incorporation of linear damping into computational models of mechanical systems

Zapomel J., Malenovský E.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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1998

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z. 8

91-94

EN

Material damping can significantly influence the behaviour of mechanical systems and therefore it is necessary to deal with approaches of its incorporation into computational models ( proportional damping, Rayleigh damping, Kelvin-Voigt theoretical material, etc. ). In the contribution there are described the determination of damping parameters starting from the material constant - specific damping capacity and comparsion of different manners of setting up the linear damping matrix through the way of computer experiment.