Web Crippling
Web Crippling
(OP)
Will somebody please check my math?
AISC/ASD 9th Edition, Equation (K1-5)
I have a W8x24, Fy=50 ksi, bearing 6" on a solid grouted, concrete masonry bond beam. I have approximately 4K of solid grouted concrete masonry bearing on top of the bearing end of the beam. The allowable compressive force that I am calculating (1219 lb) seems so low, I am convinced I am misunderstanding something.
Any comments?
Thank you!
AISC/ASD 9th Edition, Equation (K1-5)
I have a W8x24, Fy=50 ksi, bearing 6" on a solid grouted, concrete masonry bond beam. I have approximately 4K of solid grouted concrete masonry bearing on top of the bearing end of the beam. The allowable compressive force that I am calculating (1219 lb) seems so low, I am convinced I am misunderstanding something.
Any comments?
Thank you!






RE: Web Crippling
RE: Web Crippling
RE: Web Crippling
Yes! AISC, 9th, page 2-31 is where I started. My max end reaction is 66K. But then the web crippling formula fails my design intent. Both of the two conditions need to be considered.
I've checked my units. Have either of you run the formula?
Please give it a try and let me know what you come up with.
Thank you!
RE: Web Crippling
N = 6 in.
d = 7.93 in.
tw = .245 in.
tf = .4 in.
Fyw = 50 ksi
Eq K1-5 -
R = 38.5 kips
RE: Web Crippling
N = 6.0 inches bearing length
d = 7.93 inches beam depth
k = 0.875 inches
tw = 0.245 inches web thickness
tf = 0.400 inches flange thickness
Fy = 50 ksi
RE: Web Crippling
What am I doing wrong?
(34*(0.245)^2)*(1+3*(6/7.93)*(0.245/0.4)^1.5)*(SQRT(50000*0.4/0.245))=1217 lb
Thank you!
RE: Web Crippling
Maybe you have caught the error but if not, the Fyw of steel must be in ksi since the formula is the max end reaction in (kips)
RE: Web Crippling
My trial is over!
Thank you!
RE: Web Crippling
You bring up a good point to remember, that is, when your gut gives you that "funky feeling" that something isn't right - it usually isn't. Listen to your gut feelings!
We all make mistakes, the key is to find them before they cause a problem. Many times you get a feeling that something is wrong, but you can't quite put your finger on it. Listen to that feeling and look at the problem from a different angle.
RE: Web Crippling
I agree with jheidt2543, thats what these forums are for. When in doubt looking at it with other people helps.
Have a good one guys and gals