Vibration damper
A vibration damper is a system for damping mechanical oscillations ( vibrations , shocks , shocks ). The aim is to kinetic energy into heat energy to convert. A basic distinction is made between the following systems:
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Friction brakes operate frequency- independent, and are supported on a counterpart which is either at rest or a different resonant frequency comprises
- Linear oscillations are about by inaccurate as a " shock absorber reduces designated" vibration dampers that are part of the suspension of most sprung vehicles are.
- Torsional vibrations are reduced by torsional vibration dampers such as flat surface dampers .
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Resonant systems , see resonance absorption with mechanical vibrations
- Linear vibrations can be limited by so-called vibration absorbers , which are tuned to certain frequency ranges, move freely with the vibrating object and do not require any external anchoring.
- Torsional vibrations can be reduced, for example, by a two-mass flywheel , which couples two centrifugal masses with one another using spring elements in order to be able to elastically absorb vibrations and torque peaks and to be able to (partially) release the kinetic energy stored in the process.
- Influencing the resonance frequency by changing the mass or stiffness of the construction in order to avoid oscillation due to external stimulation.
Vibration dampers on tall structures
Pendulum absorbers can only dampen vibrations of a very specific frequency. They are installed near the highest point of tall structures, for example at the top of the Berlin television tower .
Masts and overhead lines
Rope-anchored tubular steel masts also tend to vibrate induced by wind, which is why chambers filled with soft granulate are often attached to dampening vibrations, for example on the transmitter masts of the marine transmitter DHO38 . Rope Anchored steel lattice masts however, show a lower tendency to oscillate as they have a smaller windage. Weights that are attached to the guy ropes can also help suppress vibrations by influencing the resonance frequency.
Conductor ropes from overhead line pylons are excited to vibrate by the wind, which can lead to a short circuit or a broken cable . For this reason, so-called Stockbridge vibration absorbers are installed here - especially for long spans . These consist of a short piece of rope with weighted ends, which is clamped parallel to the conductor cable near the suspension at the bottom.
Other ways of damping vibrations in electricity pylons are
- Additional weights on the isolators ,
- Elastomer storage of the individual parts in the spacers of multiple conductors and
- Elastomer spirals around the ends of conductor cables with an optical fiber in the core.
