Structural Engineering: RE: Radius of Gyration

I agree 110% with your take on first principles. I was taught the proof in terms of what Thor had posted - but that is actually what originally lead me to this question... it relates to a distance rather than a radius (the proof in these terms only works along the axis of concern - in a straight line only - and would yield a different "radius" for any given direction) and doesn't appear to have anything to do with gyrating... but your explanation answered it fully. However, I don't know that having such a level of understanding will help in my career - interesting, but not really practical. Case in point, my current mentor is in his 80's and is among those who didn't know the answer to this one, and he definitely knows what he is doing.
I'm supposing that it is your extended training in dynamics as a mechanical guy that lead you to this additional insight - seeing as how it may actually be useful in some such tasks. Thanks for the software links on your website BTW, very useful.

-----Original Message-----
From: Christopher Wright [mailto:chrisw@skypoint.com]
Sent: Sunday, June 21, 2009 11:43 AM
To: seaint@seaint.org
Subject: Re: Radius of Gyration

On Jun 21, 2009, at 7:48 AM, Richard Calvert wrote:

>
> And now I know. So, thank you Chris for satisfying a ~6 year old
> curiosity. Albeit snidely... but thanks just the same.
Engineers of my advanced years have reputations to maintain. (But I
really thought my English was pretty good, snide or not)

But I really am serious about first principles.

Christopher Wright P.E. |"They couldn't hit an elephant at
chrisw@skypoint.com | this distance" (last words of Gen.
.......................................| John Sedgwick, Spotsylvania
1864)
http://www.skypoint.com/members/chrisw/

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