Stiffener detail to create a hole in W-beam 1

[engr567]

Can anyone please give a typical stiffener detail to create a hole in a W beam? I would really appreciate it. In my case, I need to create a 12" wide x4" high hole (at the mid-depth of the beam) in a W16x36 beam.
Thanks in advance.

 

[alfie0077]

I am a architectural body, not steel. Yet in architecture and building design, the ends have to be kept. all holes must be in the center of each beam. (The edges hold all the stress and compression. So, center it as much as possible on the flats. There are formulas which I do not have that tells how much meat you have to keep at the edges. As a rough guess, keep 3x the thickness at least if possible.

 

[neffers]

check out aisc design guide #2...you may not even need reinforcing around the web penetration.

http://www.aisc.org/store/p-1540-design-guide-2-design-of-steel-and-composite-beams-with.aspx

neffers

 

[BAretired]

Calculate the maximum shear at the end of the opening. Call it V kips. The secondary moment in the top and bottom portion of the beam as a result of the opening is M' = Vw/4 where w is the width of opening. In your case, M' = 3V"k. Combine this with primary moment, M to find stresses.

Add an angle each side of the web, top and bottom such that bending stresses are acceptable. Extend the angles at least 6" beyond the opening.



BA

 

[ishvaaag]

Great compressed guide, BAretired.

 

[engr567]

Thanks BAretired.