Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

2 Archives of Acoustics

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Experimental study of sound transmission loss in electrorheological fluids under DC voltage

100%

Szary M. L.

tom Vol. 27, no. 3

229-240

The electrorheological (ER) liquids possess the ability to change their physical properties like the apparent viscosity and modulus of elasticity which is related to stiffness under influence of external electric field. They serve successfully in the field of semi-active/active vibration control - as well as in many other areas. The STL was investigated for various kinds of ER suspensions in the frequency range from 100 Hz to 2 kHz. An influence of the electric field density on the STL was different for normal and tangential sound wave propagation. In both cases the STL decreases with the increasing electric field density. Those properties can be potentially useful in sound propagation control applications.

The Study of Behavior of Vibrating Systems Controllable by Devices with Rheological Fluid

63%

Szary M. L. , Weber P.

tom Vol. 38, No. 2

217--222

The nonlinear mathematical model of behavior of controllable viscosity fluid (CVF) under applied external field is presented. A large family of these fluids is commonly used to control responding forces of dampers in vibration control applications. The responding force of a damper with CVF has two components. The first one - uncontrollable - is proportional to the viscosity of a base fluid and velocity of its motion, the second one, which is controllable, depends on the strength of the applied external field. Both are involved in the process of dissipation of unwanted energy from the vibrating systems. An equivalent damping factor based on the principle of energy dissipated during one cycle of damper work under a constant strength external field was calculated. When mass or stiffness is variable the equivalent damping factor can be set accordingly by adjusting the strength of external field to have vibrating damped system purposely/continuously working in the critical or other chosen state. This paper also presents cases of applying periodically changing strengths of an external field synchronized with cycles of periodical motion of the vibrating system to continuously control the damping force within each cycle.