Max Deflection on a Beam

[Layne13]

Hello, I was wondering if someone could help out.

My problem, need to find the max deflection along a beam with a center load of 500lbs. The beam is a typical I beam I4X13, that will be braced at both ends 17 feet above the ground. The Ixx = 11.3in^4
Iyy = 3.86in^4

Hoping to see the calculations to better understand it myself.

Thanks!

 

[ishvaaag]

Hmm... difficult task without giving the span of the beam. For ordinary cases will be just applying a formula.

 

[Layne13]

Sorry, span is 13 feet.

 

[csd72]

Layne13,

If this is an assignment then very few engineers calculate deflection from first principles, we mostly tend to use deflection formulii such as those found in the back of steel designers handbooks.

 

[Layne13]

No, not an Assignment. Looking to place a mixer for a pH tank on a I4x13 beam above the tank. Just wanting to make sure the Deflection will be less than an Inch. Looking at a max load of 500 lbs, (equipment and worker). So checking to see if this will be adequate or if I need to go with a larger beam.

 

[csd72]

The equation is PL^3/48EI

 

[Stillerz]

PL^3/48EI + 5WL^4/384EI ....don't forget your beam weight!!!
Also, your beam will be a lot stiffer if it is deeper, even at the same 13 lb/ft weight. Just something to consider.

 

[msquared48]

You will get the same deflection at the center if you just add half of the beam weight into the P load in the first equation. Works for this case, but not all by any means.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[Layne13]

Thanks for all the feedback. Really did help a lot.

 

[BAretired]

Neglecting the beam weight, your deflection is about 1/8" so no problem!

BA