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

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

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Page 1: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 2: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 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 loadsBEAM-COLUMNS 200

Page 3: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 4: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 5: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 6: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 7: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 8: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 9: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 10: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

Shear force is transmitted

primarily through which

component(s) in this beam-to-

column connection?

The bolted (double) web angles

SHEAR/CONC. LOADS 100

Page 11: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 12: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 13: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 14: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

Name all flexural (strength) limit states for beams.

Yield, flange local buckling, web local buckling, lateral

torsional buckling

BEAMS 300

Page 15: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 16: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 17: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 18: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 19: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 20: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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

Page 21: BEAMS(FLEXURE)BEAM-COLUMNS SHEAR / CONC. LOADS WILDCARD 100 200 300 400 500

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