Would you design this member as a column or beam-column and why?
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Transcript of Would you design this member as a column or beam-column and why?
BEAMS(FLEXURE
)
BEAM-COLUMN
S
SHEAR / CONC. LOADS
WILDCARD
100 100 100 100
200 200 200 200
300 300 300 300
400 400 400 400
500 500 500 500
Would you design this member as a column or beam-column and why?
Beam-column; since connections to it are moment connections, it is probably used to resist moments
due to lateral loadsBEAM-COLUMNS 200
Would you design this member as a column or beam-column and
why?Column; the shear tabs theoretically transfer no moment
to the columnBEAM-COLUMNS 100
Explain the basic concept behind B1 and B2 for beam-
columns.Moment amplification due to 2nd order effects – the result of the axial forces acting on the deformed shape of the beam-column and causing additional
moment. BEAM-COLUMNS 300
ltntu MBMBM 21
Explain why there is one value of ‘by’ for each W-shape in Table 6-1.
‘by’ captures the weak-axis flexural member capacity, which
is independent of unbraced length, Lb, since lateral torsional
buckling does not occur for bending about y-axis
USE AISC ManualBEAM-COLUMNS 400
Would use of Table 6-1 values (unmodified) to
size these beam-columns likely be
somewhat conservative and why or why not?
Yes; the table is based on Cb=1.0, and these beam-columns are subject to
reverse curvature, and Cb could be > 2.0
BEAM-COLUMNS 500
What do you think this
construction worker doing?
And why?
The bolt holes didn’t line up. He’s using a torch to fix the
problem.WILD CARD 200
BOLTS
TORCH
Note: this question is just for fun; not within scope of Final Exam
What is likely providing the resistance to lateral loads in this
steel frame?Rigidity of connections and flexural stiffness of beams and
columns WILD CARD 100
What is the impact of the small welded connections in this truss?
The “stitching” effectively increases the out-of-plane
buckling capacity of the double angle compression membersWILD CARD
300
Note: this question is NOT within the scope of the Final Exam
Shear force is transmitted
primarily through which
component(s) in this beam-to-
column connection?
The bolted (double) web angles
SHEAR/CONC. LOADS 100
The above equation for shear resistance for
rolled I-shaped members is applicable only if this condition is
satisfied.h/tw is less than the limit for
inelastic shear buckling
SHEAR/CONC. LOADS 200
vwywn CAFV )6.0(0.1
Name two limit states which must be checked for this beam-to-girder connection and depend upon thickness of the beam web.
Bolt bearing and block shear(+ flexural yield, rupture, buckling)
SHEAR/CONC. LOADS 500
Suppose this beam is a W16x26. What is the shape
factor for x-axis bending?Zx/Sx = 44.2/38.4 =1.15
BEAMS 100
BEAM
USE AISC Manual
Name all flexural (strength) limit states for beams.
Yield, flange local buckling, web local buckling, lateral
torsional buckling
BEAMS 300
The hole in the column web can be used to lift the column into place.
The plates are for ……splice and transfer of forces from the column to be placed
above.WILD CARD 400 Note: this question is just for fun; not within scope of Final
Exam
You are asked to check flexural capacity of this beam with regards to construction loads as well as the full factored design
load (after deck is attached and concrete cast). What Lb would you consider for each
case for a beam of length L?Construction Lb=L; Full factored Lb=0
BEAMS 200
BEAM
Why are lp and lr different for webs of beams as opposed to flanges of
beams?
These are limits for local buckling, and critical buckling loads depend on
loading conditions (i.e. pure axial compression or flexural compression)
and edge support conditions (i.e., stiffened or unstiffened)
BEAMS 500
This girder will have 6 beams framing in on each side. Your colleague says
that clearly Cb=1.14 if equivalent uniform loading is assumed. You
say…?1.14 would be for no lateral bracing at loads; this Cb would be
closer to 1.0BEAMS 400
GIRDER
USE AISC Manual
Where might stiffeners be required in this beam-column joint?
In the column web, at the flange angles (concentrated
loads from the moment connection)SHEAR/CONC.LOADS
300
Calculations show that a W16x50 has adequate shear and moment
capacity for the design loads, but a W21x50 is used. What is a likely
reason for this?The need for larger flexural
stiffness (Ix) because of serviceability (deflection) limits
WILD CARD 500
Beam #1 rests on and exerts 0.5 kip on beam
#2; how many more #1’s could be placed
(one on top of another) before causing local web yielding in #2?
Both beams are W18x35’s (A992 steel).Rn=f(5k+lb)Fywtw =1.0(5(0.827”)+6”)
(50ksi)(0.3”)=152 kips 152/0.5 = 304 beams
SHEAR/CONC.LOADS 400
USE AISC Manual
#1
#2