Resonance danger
#51
Senior Member
So many words, so much wrong. Read up on Hopf bifurcation. https://silca.cc/blogs/marginalgains...marginal-gains or if you prefer https://en.wikipedia.org/wiki/Hopf_bifurcation
There's been a great study on bike stability by folks from Delft and Cornell et al, they made an excellent simulation model, but I think it's only valid for basic stability (steering into a fall), and not wobble dynamics. But very good if you can find online, I myself have the PDF but can't really post that without a link.
EDIT: Reading again the above study, I found this: "All known bicycle and motorcycle designs lose self-stability at high speeds because of gyroscopic terms." (Whereas at lower speeds, gyroscopic forces increase stability.)
EDIT: Excellent article:
https://velo.outsideonline.com/road/...-to-stop-them/
Last edited by Duragrouch; 04-15-24 at 07:44 PM.
#52
Newbie
Yes, dampen is very often used in those contexts, such as to dampen enthusiasm, analogous to "raining on your parade", drowning a good idea, extinguishing a fire (or idea) with water.
Similarly, dampener is something that can make something wet or quell enthusiasm like noted above, whereas damper is a device to reduce motion or energy, or flow, like a furnace damper.
No worries. I was one of those people who referred to casual cotton twill slacks as "khakis", until I heard the enlightening quote I mentioned. I hope you took my comment in a friendly way. But I can definitely understand issues with language translation; Though I have an ear for accents, I have a terrible mind for vocabulary in a foreign language, that has prevented my achieving any level of fluency in any of them.
And listen, the USA has had leaders in government who pronounced "nuclear" (new-clee-ur) as "nucular". So I'm very impressed with your knowledge and command of english, compared to my zero knowledge of your language (from your profile, Serbian?).
Similarly, dampener is something that can make something wet or quell enthusiasm like noted above, whereas damper is a device to reduce motion or energy, or flow, like a furnace damper.
No worries. I was one of those people who referred to casual cotton twill slacks as "khakis", until I heard the enlightening quote I mentioned. I hope you took my comment in a friendly way. But I can definitely understand issues with language translation; Though I have an ear for accents, I have a terrible mind for vocabulary in a foreign language, that has prevented my achieving any level of fluency in any of them.
And listen, the USA has had leaders in government who pronounced "nuclear" (new-clee-ur) as "nucular". So I'm very impressed with your knowledge and command of english, compared to my zero knowledge of your language (from your profile, Serbian?).
By the way, in these parts of the world people will say things like "Toyota jeep", because jeep is a synonym for a terrain vehicle or SUV, probably since WW2. Things became a bit uncomfortable when the actual Jeep brand arrived on this market...
#53
Senior Member
I lived in the USA long time ago and had a hard time convincing people to correct me at least when they thought they should (but didn't because they were very nice and tolerant). So no, I have absolutely no problems with you, or anyone else, correcting me or explaining the nuances - I like to learn.
By the way, in these parts of the world people will say things like "Toyota jeep", because jeep is a synonym for a terrain vehicle or SUV, probably since WW2. Things became a bit uncomfortable when the actual Jeep brand arrived on this market...
By the way, in these parts of the world people will say things like "Toyota jeep", because jeep is a synonym for a terrain vehicle or SUV, probably since WW2. Things became a bit uncomfortable when the actual Jeep brand arrived on this market...
In the USA "south" (meaning southeast), some refer to all carbonated drinks as a "Coke" (from Coca-Cola). So it is common for someone there to request an "orange coke" or "lemon coke" or "rootbeer coke", etc. And actual Coke is "Co-cola".
Just in the news tonight, a very renowned USA journalist has died, Robert ("Robin") MacNeil, originally from Canada, among his many books he had written one on the history of the English language, and then later one about all the different regional dialects in the USA, titled, "Do you speak American?"
#54
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FFS
#55
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It seems to me that the mathematician that introduced the cycling world to Hopf bifurcations didn't even look at the dynamics of a bicycle, so it bothers me a little that people talk about it like it's something that ends arguments about speed wobble/shimmy. I hate to have to listen to a podcast to learn if what the silca guy said shed any light on the matter. If you don't tie it back to a physical model with predictive power, it doesn't really settle anything.
There seems to be an international split in the vibration engineering community over "damping" vs. "dampening." In the U.S., vibration engineers generally assert that "dampening" is the process of getting something wet. But outside the U.S., "dampening" is often used to mean something that removes energy from a vibrating system. Both words have the same root, so it's difficult to make an argument either way based on linguistics.
There seems to be an international split in the vibration engineering community over "damping" vs. "dampening." In the U.S., vibration engineers generally assert that "dampening" is the process of getting something wet. But outside the U.S., "dampening" is often used to mean something that removes energy from a vibrating system. Both words have the same root, so it's difficult to make an argument either way based on linguistics.
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#56
Senior Member
(above) Vaild on both points. Please see my edit at the bottom of my post #51; I wish I could post that PDF here. I may try to look for where I originally found that and post a link. Good study.
#57
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There seems to be an international split in the vibration engineering community over "damping" vs. "dampening." In the U.S., vibration engineers generally assert that "dampening" is the process of getting something wet. But outside the U.S., "dampening" is often used to mean something that removes energy from a vibrating system. Both words have the same root, so it's difficult to make an argument either way based on linguistics.
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#59
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And all these years I'd been thinking I was the only one who bothered. "Managers" mostly seemed to behave as though it was their job to leave making mistakes to others then claiming credit for what worked.
BTW thanks for posting links to that Silca stuff. Never stumbled across that before, lots to absorb!
Last edited by spclark; 04-18-24 at 07:08 AM.
#60
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WHOA! What an original concept! [/sarc]
And all these years I'd been thinking I was the only one who bothered. "Managers" mostly seemed to behave as though it was their job to leave making mistakes to others then claiming credit for what worked.
BTW thanks for posting links to that Silca stuff. Never stumbled across that before, lots to absorb!
And all these years I'd been thinking I was the only one who bothered. "Managers" mostly seemed to behave as though it was their job to leave making mistakes to others then claiming credit for what worked.
BTW thanks for posting links to that Silca stuff. Never stumbled across that before, lots to absorb!