Reinforcing a beam for shear - is it possible?
Reinforcing a beam for shear - is it possible?
(OP)
We are trying to determine whether or not it is possible to reinforce a W24x250 beam for shear near a support. Since the shear is only in one small portion of the beam, it seems uneconomical to increase the size of the already enormous beam when it is just one small portion that needs more shear capacity and the flexural capacity is ok. We had thought about welding a doubler plate to the web to increase the web cross section area in the high shear area, but we have not been able to find much info on whether or not this is a very effective solution.
Has anybody had success with a doubler plate or something similar to increase shear capacity in a beam?
A diagram for clarity...
720k
|
V
==============================================
XXXXX <--- doubler plate?
W24x250 (spanning over top of W24x250)
XXXXX
==============================================
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| W24x250
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Has anybody had success with a doubler plate or something similar to increase shear capacity in a beam?
A diagram for clarity...
720k
|
V
==============================================
XXXXX <--- doubler plate?
W24x250 (spanning over top of W24x250)
XXXXX
==============================================
-----
|
| W24x250
|
-----






RE: Reinforcing a beam for shear - is it possible?
Mike McCann
MMC Engineering
RE: Reinforcing a beam for shear - is it possible?
RE: Reinforcing a beam for shear - is it possible?
The W24x250 (Fy = 50) provides 738.5 kips of shear capacity (φVn per AISC 360-05, Section G2.
Section G3 offers a tension field option to look at - not sure what capacity this would offer.
Section J10 discusses the doubler plate usage.
RE: Reinforcing a beam for shear - is it possible?
RE: Reinforcing a beam for shear - is it possible?
RE: Reinforcing a beam for shear - is it possible?
RE: Reinforcing a beam for shear - is it possible?
The top W24 is bearing on the bottom W24 at a 22.5 degree angle, and has the same conditions at the opposite end with the same shear and bearing on a W24 at a 22.5 degree angle. The bottom support steel is in the shape of an octagon attached to 8 columns. The upper steel is in the shape of an octagon as well, but is rotated 22.5 degrees relative to the lower steel. This upper octagon of steel is to provide continuous support to a cement silo with some pretty massive loads. The upper octagon of steel bearing on the lower octagon of steel is necessary because the lower octagon of steel is at too large of a radius to provide continuous support to the silo.
Thanks all for your input, it is very helpful to get some other ideas on how to tackle this.
RE: Reinforcing a beam for shear - is it possible?
A small region of an I-beam shear web with all the stress and stability concerns neatly spelled out.
I'm not sure if AISC has a section on this, but I bet the Canadian CISC hdbk has this.
tg