# BEAMS (FLEXURE) BEAM- COLUMNS SHEAR / CONC. LOADS

## Presentation on theme: "BEAMS (FLEXURE) BEAM- COLUMNS SHEAR / CONC. LOADS"— Presentation transcript:

100 200 300 400 500 BEAMS (FLEXURE) BEAM- COLUMNS SHEAR / CONC. LOADS
WILD CARD 100 200 300 400 500

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 loads BEAM-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 column BEAM-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

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 Manual BEAM-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?
BOLTS TORCH 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. Note: this question is just for fun; not within scope of Final Exam WILD CARD 200

Rigidity of connections and flexural stiffness of beams and columns
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?
Note: this question is NOT within the scope of the Final Exam The “stitching” effectively increases the out-of-plane buckling capacity of the double angle compression members WILD CARD 300

The bolted (double) web angles
Shear force is transmitted primarily through which component(s) in this beam-to-column connection? The bolted (double) web angles SHEAR/CONC. LOADS 100

h/tw is less than the limit for inelastic shear buckling
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

Bolt bearing and block shear (+ flexural yield, rupture, buckling)
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

BEAM Suppose this beam is a W16x26. What is the shape factor for x-axis bending? Zx/Sx = 44.2/38.4 =1.15 USE AISC Manual BEAMS 100

Name all flexural (strength) limit states for beams.
Yield, flange local buckling, web local buckling, lateral torsional buckling BEAMS 300

…splice and transfer of forces from the column to be placed above.
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. Note: this question is just for fun; not within scope of Final Exam WILD CARD 400

Construction  Lb=L; Full factored  Lb=0
BEAM 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

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

GIRDER 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 1.0 USE AISC Manual BEAMS 400

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
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). #1 #2 Rn=f(5k+lb)Fywtw =1.0(5(0.827”)+6”)(50ksi)(0.3”) =152 kips  152/0.5 = 304 beams USE AISC Manual SHEAR/CONC.LOADS 400