How do Vibration Dampers Stop Transmission Line Failures?

[@MaximilianBrandt]

I do have to ask though, why is it shaped in the way it is? I know what dampers are and how they work, just I never quite saw this particular design.

[@instazx2]

yeah that shape is certainly *a choice* by the engineers, lmao. guess there was no other way to do it.

[@jhonbus]

That's an inherent part of the way they work. Imagine looking at the point where the clamp attaches to the power line. as a vibration passes through it. It shows up as the connection twisting first one way, then the other as the wave passes that point. The weights on the damper are at the end of lever arms, giving them a high moment of inertia, and meaning it takes a lot of force to twist the damper, which absorbs energy from the vibration on the power line. Two other features then become important to make sure the energy isn't simply returned from the damper back into the power line: First. the length of the arms and the mass of the weights are chosen so that the response frequency of the damper is matched to the main frequency of the aeolian vibrations expected in the power line. This can be worked out based on several factors like cable material, line tension, wind speed, etc. This tuning means that the damper applies a force out of phase wit the input force, canceling out the main vibration modes. Secondly, and less importantly, the damper arms are made of somewhat flexible cable rather than a stiff bar. Flexing of these arms introduces parasitic losses due to heating. This is normally a small effect but in the case of an unlucky set of conditions (wind speed happens to be just right (just wrong?) so that it sets up a vibration at the resonant frequency of the line and damper system, ) the flexing in the damper will become much larger than normal and inelastic losses will become a lot higher, which can both absorb more vibrational energy but also can result in a shifting of the damper response frequency, taking it out of resonance. This prevents a resonant vibration building and building to the point something catastrophic happens. (see Tacoma Narrows bridge)

[@instazx2]

@@jhonbus right but does it have to look like a man's block & tackle, lol

[@MaximilianBrandt]

@@jhonbus I was more meaning of why the weights are shaped quite so phalically. Two weights on a wire make sense after all - that is a no brainer.

[@nandhakumar.r2690]

I am an engineering student your videos are very informative 👍👍

[@AxisElectrical]

I am glad you find our videos informative 🙌