About web opening in S beam or W-beam
About web opening in S beam or W-beam
(OP)
If there is a web opening in W section we normally design it using the formulae or methods specified by Steel Design guide 2 "Steel and composite beam with web opening" but if the W beam is cut to T section somewhere along the length, could we still use the method an formulae.
Secondly could we use the method for S-shaped beams too.
Thanks for reading and I appreciate your response.
Secondly could we use the method for S-shaped beams too.
Thanks for reading and I appreciate your response.






RE: About web opening in S beam or W-beam
I see no reason why S-shapes would not use the same formula though you should check the formula assumptions before using them.
RE: About web opening in S beam or W-beam
RE: About web opening in S beam or W-beam
Last question : If angles are provided how to determine how much development is required at both ends..
Thanks for the response..
RE: About web opening in S beam or W-beam
1) Can i use the formulae from " Design guide 2 "Steel and composite beam with web opening"", if the W -beam is cut to a t-beam along the length for a duct to pass through.
2) what checks do i need to consider in the design?
RE: About web opening in S beam or W-beam
2) Check bending, shear, longitudinal shear capacity in reinforced reduced section (and the welds). The angles need to be sufficiently long so that the bottom flange force can be transferred to the original flange via longitudinal shear of the web. You also need to check overall buckling, and this is where it may get interesting.
RE: About web opening in S beam or W-beam
It is Steel design guide series 2
2) How do i check the length of the angle member is sufficient and check for overall buckling. Is there any good reference material.
Thanks again for the comment.
RE: About web opening in S beam or W-beam
RE: About web opening in S beam or W-beam
If you are lopping off a flange somewhere along the length, this is a different scenerio, and you need to analyze it as csd suggested.
RE: About web opening in S beam or W-beam
The duct that is passing through cuts through the bottom part of flange and web. So the bottom part of the flange is cut just for short distance...
RE: About web opening in S beam or W-beam
RE: About web opening in S beam or W-beam
RE: About web opening in S beam or W-beam
1) my comment is that they did not use the word WEB by accident in the title, this publication refers to openings in the WEB not the flanges and therefore is not directly applicable.
2) If this beam is simply supported and the compression flange is restrained then buckling should not be a problem as long as the stresses are within the allowable section stresses. If this is a continuous or framed beam then this is a much more complicated matter the cutout constitutes a discontinuity in the effective length of the bottom flange - the easiest way to rectify this is to provide fly braces each side. Keep in mind that this discontinuity issue applies even if the cutout section is in tension as this still effect the effective length for the end moments.
This is something that should not have been done, dont feel guilty about going a little over the top to make yourself comfortable that it will work.
RE: About web opening in S beam or W-beam
for your comments