Logging Vibrations

[hardingfv32]

Rod Nelson, Williams, talking about winter testing: "But you'd be doing the aero testing anyway - you'd be flow-vising diffusers and logging vibrations anyway."

What area of design does 'logging vibrations' relate to…. aero or mechanical? What kind of information can be gleaned from vibrations?

Brian

[bill shoe]

When a new airplane design is put together for the first time, it typically spends much time getting tested for vibration frequencies and modes before actually flying. The structure has a small margin of safety, and therefore you want to make sure the physical system works dynamically like your simulation says it does. If physical test confirms the sim then you're ready to fly. I think they would look at freqs, mode shapes, and amplitudes in response to inputs that correspond to typical and severe flying conditions.

F1 is similar, you want the dynamic system/car to behave like your sim says it should. Safety is not quite as critical as in a plane, but lack of correlation between what you designed to occur and what actually occurs is a red flag for reliability problems if nothing else.

More specific info from anyone?

[DaveKillens]

All systems can resonate. Those vibrations can get amplified, and in the worst-case scenario, the part fails. The most famous large scale example is Galloping Gertie, a suspension bridge that was destroyed by runaway vibrations.



It could be a wing strut, or a suspension arm, it could be anything.

Another example is a motorcycle steering damper, put in place to dampen out oscillations of the front forks.

[Tim.Wright]

I'd say that given aero-elasticity is explicitly allowed in the regulations (while simultaneously being banned!?) then measurement of the deformation due to the various road frequencies is a pretty important activity to stop wings from failing or performing badly due to resonance.

[trinidefender]

Start reading people. A paper that I have only just started reading. It is on how vibration affects wings concerning the boundary layer. Admittedly this isn't a topic I know to much about but that's why I am reading this paper.

http://www.researchgate.net/publication ... ng_surface

[PlatinumZealot]

Rod Nelson, Williams, talking about winter testing: "But you'd be doing the aero testing anyway - you'd be flow-vising diffusers and logging vibrations anyway."

What area of design does 'logging vibrations' relate to…. aero or mechanical? What kind of information can be gleaned from vibrations?

Brian

Voticies and turbulence I guess. Like a reed vibrating in a river.