Max Point Load on Steel Angle
Max Point Load on Steel Angle
(OP)
Hello All -
I'm doing some studying for the PE exam in only 4 short days. There is one aspect of a practice problem I'm working on that is not makng sense to me. The problem is: one leg of a A36 L6x6x3/8x6" steel angle is fastened to a concrete wall with an expansion anchor. The other leg supports a point load (4" away from the face of the concrete wall). Assume the concrete is sufficient and assume the expansion anchor is sufficient. Find the max point load P that can be supported.
The ASD solution goes about treating the supporting angle leg as a thin beam.
S=1/6*6*0.375^2=0.141 ksi
Fb=0.75*36=27 ksi
Mr=0.141*27=3.8 in-K
Pmax=Mr/e=3.8/4=1.0 K (answer)
I follow the solution entirely except for one detail. When the calculate the Allowable bending stress Fb, they use a factor of 0.75. Where is this 0.75 coming from? In my mind, I think the factor should be 0.66? Any insight on this problem is greatly appreciated! Thanks!
I'm doing some studying for the PE exam in only 4 short days. There is one aspect of a practice problem I'm working on that is not makng sense to me. The problem is: one leg of a A36 L6x6x3/8x6" steel angle is fastened to a concrete wall with an expansion anchor. The other leg supports a point load (4" away from the face of the concrete wall). Assume the concrete is sufficient and assume the expansion anchor is sufficient. Find the max point load P that can be supported.
The ASD solution goes about treating the supporting angle leg as a thin beam.
S=1/6*6*0.375^2=0.141 ksi
Fb=0.75*36=27 ksi
Mr=0.141*27=3.8 in-K
Pmax=Mr/e=3.8/4=1.0 K (answer)
I follow the solution entirely except for one detail. When the calculate the Allowable bending stress Fb, they use a factor of 0.75. Where is this 0.75 coming from? In my mind, I think the factor should be 0.66? Any insight on this problem is greatly appreciated! Thanks!






RE: Max Point Load on Steel Angle
Finally, using an e of 4" would be conservative for checking the angle. You can typically be pretty conservative using e = 4" - the thickness of the angle.
RE: Max Point Load on Steel Angle
RE: Max Point Load on Steel Angle
RE: Max Point Load on Steel Angle
That's the way I just did it yesterday.... but I'm just lazy. I didn't feel like looking in the 13th edition manual.
RE: Max Point Load on Steel Angle
You'll probably find that your PE test is practical like this problem for the most part.
RE: Max Point Load on Steel Angle
Anyone know where in the steel manual the 0.75 factor is coming from? I've looked through Chapter F in the specifications and can not find 0.75 listed in any of the cases?
RE: Max Point Load on Steel Angle
See this link for a similar topic....floor plate bending.
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RE: Max Point Load on Steel Angle
I get 0.9 from (1/1.67)*1.5 = (1/omega)*(shape factor=Z/S=1.5 for rectangular section) = (1/1.67)*1.5 = 0.9Fy
RE: Max Point Load on Steel Angle
I'd move on, study for other parts of the test.
RE: Max Point Load on Steel Angle
EIT
RE: Max Point Load on Steel Angle