Isn't this shown in the 3rd row in the tables "tension in beams, extreme fiber, net section" for "round or oval tubes"? Also referenced in section 3.4.3. From my understanding there is only one check for extreme fiber tension in a beam whereas many sections for checking the compression due to buckling of such custom and thin shapes, hence all the other sections with varying formulas depending no how an element of the shape is braced or stiffened.
I am referring to aluminum rod and I would guess that 3.4.3 refers to round tube and not rod? (I see the round sections listed explicitly for compression in 3.4.13.) I must be missing something as I do not understand why I don't see the round rod allowable stress for bending in beams. Any other ideas? Thanks!
Ah, now I understand. I'm not sure the tension face of a solid round member would control over the compression face. For this reason, I don't recall the ADM having a check for tension in bending of a rod shape. I believe 3.4.13 would be the appropriate check for a rod member. Maybe you have a unique loading application or reason for wanting to check tension in this member that I cannot think of at the moment?
Thanks - sounds good. I am a mechanical engineer who is often involved in the structural side of things in both steel and aluminum - generally I would apply the basic bending and shear calculations (generally use the same allowable for tension and compression) to the beam with appropriate safety factor but thought I would work through my analysis using the ADM method this time and see if any difference.
Aesur, another question related to 3.4.13 - the slenderness calculation uses depth and thickness. With a rod column, I understand how I would calculate the slenderness ratio but in this instance, is a 1" round bar "beam" for example treated the same way as a 1"x1" square "beam"? (d/t * sqrt(L/d) i.e. What is "d" and what is "t" if we are not talking about flat sections?
Check out pages I-A-32 & I-A-33 of the ADM 2005. d is depth of section, t is thickness of section, if we talking about a round bar, I would say d=t, therefore d/t = 1.
