1. ## Material strenght question...

Hello everyone,
Question for you engineering types:
Does anybody know the formula for 6061 T6 deflection strenght / max deflection and that for steel tubing? I'm trying to determine how much deflection will 1/2" x 2" aluminum bar deflect over 10" lever arm with ~100N of force max.

TIA
Yuriy

2. The following formula is for a cantilevered beam only. Don't mix units, stick to pounds and inches and your numbers should come out okay.

Ymax = PL^3/(3EI)

Where:

Ymax = Deflection at end of cantilever beam (inches)
L = Length of cantilever beam (inches)
E = Youngs Modulus of given material(PSI)
I = Area Moment of Inertia (in^4)

E for Aluminum = 9.9E6 PSI
E for Steel= 29.0E6 PSI

I for a solid rectangular bar: I = (BH^3)/12
Where:

B = Width
H = Height

I for rectangular tubing: I = (BH^3 - bh^3)/12

Where:
B = Outer Width
H = Outer Height
b = Inner Width
h = Inner Height

Please correct me if I missed anything. Engineers DO make mistakes

3. Thanks a lot.
This is what I was looking for

Regards
Yuriy

4. Originally Posted by croosh
Thanks a lot.
This is what I was looking for

Regards
Yuriy
You can also download "beamboy". Do a google search; an excellent free program to calculate beam deflections. I find it very useful for "back of the envelope" design.