Sanity check

Mar 01, 2007 7 Replies

Well I've had a play with some of those formulas and I just want to run a sanity check on my numbers, so all of you chaps with pre-programmed pocket calculators please stand up :


50 inch EN1A bar 1 inch in diameter, load of 10 lbs in middle of the bar. What's the deflection ?

I'll tell you what I got when I've seen your answers :-)



Thanks,


Ah, I made it about 2 1/2 thou ? (I did forget to say the bar is supported both ends though.) 37 thou is nearly a millimeter which seems a long way for 10 lbs to move the middle of a 1 inch bar ?

I'm surprised it's as little as 1mm; over four feet with 10lb stuck in the middle, I'd have though rather more than that.

Peter

-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk

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My calculations (ran it through BeamBoy) show 31 thou deflection including its own weight or 18.3 thou for the 10lb alone.

This assumes 29,000ksi for the Young's modulus, 0.284 lb/in³ for the density and 0.0491in^4 for the areal moment of inertia.

HTH

Mark Rand RTFM

Darn. The site for beamboy is out of bandwidth. How big is the download?

Wes

Oops, I hope we haven't accidentally overloaded the chap's account. On the assumption that he allows free downloads, so won't mind, I've slapped my copy on my server. Try:-

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It's just under 2MB big.

HTH

Mark Rand RTFM

Thanks. The geocities site was up this morning again before I read this. I have it now.

Wes

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