Oh Boy do I have egg on my face... Yesterday I started giving some thought to an idea that I have had stuck in my head for years and decided to have another look into it. In another post (which I didn't want to shanghai that thread with this thought) and a post from the past... I declared... if you will... that a piece of tube could be stronger than a bar of equal diameter once a certain wall thickness was met. Well that's B.S. ... Crapola... Hog-wash. (As was pointed out to me more than once...)
The thing that really bugs me about my revelation on this matter is I keep wondering HOW it is that I screwed up in the past and engraved this notion in my head. It sort of feels like when you get home from a dinner date with a real hottie and discover a big dark chunk of something stuck in between your front teeth. You gotta ask yourself how long it was that you were in that unsightly state.
Only thing I can figure is that possibly in calculating for various wall thickness of tube I maybe thought the correlation of wall thickness to torsional strength was linear instead of a curve and just ran with it? Whatever the case... I see very clearly now how the notion that the tube of same diameter could exceed bar is mathematically impossible. Only wish I had given it more thought when it was pointed it out to me way back.
This doesn't squelch my "love affair for tube" as Dave put it. (funny stuff there... and sadly pretty much true) Yes... I can still marvel in its simple design and the huge benefits it affords many a design. You know... A bar with the useless part removed...!
My sincere apologies for the misinformation.
Bob
Some pretty funny stuff in that epistle Bob. Don't beat yourself up too much, he/she who has never had a fixed belief (albeit miscued) smashed down at some time, please raise your hand. My hands are firmly in my pockets.
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