How to calculate maximum beam bend?

[funnding33]

Hi all,

I faced a problem. We have a round aluminum bar as beam and it is loaded with 10pcs of flat plates around center.
How to calculate the max deflection in center. My real beam now is 70mm dia, 1250mm long, 6061 Alum. It is loaded with 20000N weight on 10pcs of plates (2000N each) which are around beam center.
The actual bend looks like 2..3mm (eye measured) which is way to much. I need about 0.5mm or so. Now considering to change this beam to 304 stainless. But before spending big $$$ wander is there any way to calculate/estimate what would be deflection then? Here is picture of this setup attached:

 

[desertfox]

Hi

Well I think you will need to increase the size of the beam section, if I take your aluminium beam as it stands and place the total load at the centre of the beam (point load) I get a deflection of 9.86mm, if I change this to steelI still get a deflection of 3.4mm.
Have a look at beam theory on this link:-

http://www.roymech.co.uk/Useful_Tables/Beams/Beam_theory.html

 

[desertfox]

Hi

If you use a circular steel beam, my rough calculation shows a diameter of 114mm and I would suggest one at least 120mm diameter because my calculations only an estimate.
Your best bet is to contact a proper structural engineer and verify the beam design correctly.