STRUCTURAL STEEL DESIGN FINAL EXAM | QUESTIONS AND
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS (100%
CORRECT) | LATEST EXAM UPDATE
Identify stiffened and unstiffened plate elements in compression. - CORRECT
ANSWER- Stiffened - a projecting piece of steel whose two edges parallel to
the direction of a compression force are supported
Unstiffened - a projecting piece of steel having one free edge parallel to the
direction of a compression force, with the other edge in that direction
unsupported
Describe local buckling and compactness within the context of columns. -
CORRECT ANSWER- Local buckling - localized plate instability
One element (web, flange, leg, stem) buckles before global buckling occurs
Compactness - if λ ≤ λr for all elements no local buckling
Explain the effect of local buckling on design strength. - CORRECT
ANSWER- May reduce design strength
Describe the behavior of a built-up compression member. - CORRECT
ANSWER- Double angle buckles flexural about the x-axis
Double angle buckles flex-tors about the y-axis
Single angle buckles between connectors about the z-axis
Sufficient connectors prevent buckling about the z-axis
Explain why a column base plate is required to transmit axial force from a steel
column to a concrete footing. - CORRECT ANSWER- It distributes loads
from the column to concrete footing; it is necessary for the column load to be
spread over a sufficient area to keep the footing from being overstressed. Loads
for the steel column are transferred through a steel base plate to a fairly large
area of the footing below.
,Explain structural difference between beams and girders with respect to load
and bracing. - CORRECT ANSWER- -Beams
Continuous bracing, includes the dead loads, live loads, and self weight
-Girders
Discrete bracing, includes the reactions of the beams and self weight
Describe various stages in flexural response leading up to the ultimate beam
capacity, the fully plastic moment - CORRECT ANSWER- -When beam is
resisting moment at each point
-Load increases 🡪 outer fiber of flanges begin to yield 🡪 yielding moves
through flanges into first fibers of the web 🡪 yielding occurs across entire cross
section
Define and determine the fully plastic moment, Mp - CORRECT ANSWER-
The moment that will produce full plasticity in a member cross section and
create a plastic hinge
Mp=FyZx
Determine if member is compact - CORRECT ANSWER- If no local buckling
occurs
Classify type of flexural failure based on unbraced length. - CORRECT
ANSWER- -Continuous bracing
Steel decking w puddle welds
Steel decking w concrete slabs and shear studs
-Discrete bracing
Other members restraining compression flange
Account for effect of residual stress on flexural strength. - CORRECT
ANSWER- They cause forces (tension & compression) with in the member
, before loads are applied which need to be accounted for when finding flexural
strength.
Define the moment gradient coefficient. - CORRECT ANSWER- -Cb - Lateral
torsional buckling modification factor
-Magnifies φMn to account for more favorable variation of moment along
unbraced length.
Explain beam coping and its effect on shear strength. - CORRECT ANSWER-
-Beam coping: the cutting back of the flanges of a beam to facilitate its
connection to another beam
-Where beams are notched, or coped shear can be a problem. Shear forces must
be calculated for the remaining beam depth
Describe the process used to manufacture steel. - CORRECT ANSWER- -
Basic Oxygen Furnace (old method)
Flame heated (using oil or coal)
Mostly raw material (65-75%)
More than 4-man hrs. per ton
-Electric Arc Furnace
Electric heated
Mostly from scrap (90-100%)
All W shapes and most other rolled shapes
About 1-man hr. per ton
Describe naming conventions used for hot-rolled structural shapes -
CORRECT ANSWER- *W - wide flanges [W]
*M - not W, S, or HP (p. 1-32)
*S - American standard (p. 1-34)
*HP - pile bearing (p. 1-36)
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS (100%
CORRECT) | LATEST EXAM UPDATE
Identify stiffened and unstiffened plate elements in compression. - CORRECT
ANSWER- Stiffened - a projecting piece of steel whose two edges parallel to
the direction of a compression force are supported
Unstiffened - a projecting piece of steel having one free edge parallel to the
direction of a compression force, with the other edge in that direction
unsupported
Describe local buckling and compactness within the context of columns. -
CORRECT ANSWER- Local buckling - localized plate instability
One element (web, flange, leg, stem) buckles before global buckling occurs
Compactness - if λ ≤ λr for all elements no local buckling
Explain the effect of local buckling on design strength. - CORRECT
ANSWER- May reduce design strength
Describe the behavior of a built-up compression member. - CORRECT
ANSWER- Double angle buckles flexural about the x-axis
Double angle buckles flex-tors about the y-axis
Single angle buckles between connectors about the z-axis
Sufficient connectors prevent buckling about the z-axis
Explain why a column base plate is required to transmit axial force from a steel
column to a concrete footing. - CORRECT ANSWER- It distributes loads
from the column to concrete footing; it is necessary for the column load to be
spread over a sufficient area to keep the footing from being overstressed. Loads
for the steel column are transferred through a steel base plate to a fairly large
area of the footing below.
,Explain structural difference between beams and girders with respect to load
and bracing. - CORRECT ANSWER- -Beams
Continuous bracing, includes the dead loads, live loads, and self weight
-Girders
Discrete bracing, includes the reactions of the beams and self weight
Describe various stages in flexural response leading up to the ultimate beam
capacity, the fully plastic moment - CORRECT ANSWER- -When beam is
resisting moment at each point
-Load increases 🡪 outer fiber of flanges begin to yield 🡪 yielding moves
through flanges into first fibers of the web 🡪 yielding occurs across entire cross
section
Define and determine the fully plastic moment, Mp - CORRECT ANSWER-
The moment that will produce full plasticity in a member cross section and
create a plastic hinge
Mp=FyZx
Determine if member is compact - CORRECT ANSWER- If no local buckling
occurs
Classify type of flexural failure based on unbraced length. - CORRECT
ANSWER- -Continuous bracing
Steel decking w puddle welds
Steel decking w concrete slabs and shear studs
-Discrete bracing
Other members restraining compression flange
Account for effect of residual stress on flexural strength. - CORRECT
ANSWER- They cause forces (tension & compression) with in the member
, before loads are applied which need to be accounted for when finding flexural
strength.
Define the moment gradient coefficient. - CORRECT ANSWER- -Cb - Lateral
torsional buckling modification factor
-Magnifies φMn to account for more favorable variation of moment along
unbraced length.
Explain beam coping and its effect on shear strength. - CORRECT ANSWER-
-Beam coping: the cutting back of the flanges of a beam to facilitate its
connection to another beam
-Where beams are notched, or coped shear can be a problem. Shear forces must
be calculated for the remaining beam depth
Describe the process used to manufacture steel. - CORRECT ANSWER- -
Basic Oxygen Furnace (old method)
Flame heated (using oil or coal)
Mostly raw material (65-75%)
More than 4-man hrs. per ton
-Electric Arc Furnace
Electric heated
Mostly from scrap (90-100%)
All W shapes and most other rolled shapes
About 1-man hr. per ton
Describe naming conventions used for hot-rolled structural shapes -
CORRECT ANSWER- *W - wide flanges [W]
*M - not W, S, or HP (p. 1-32)
*S - American standard (p. 1-34)
*HP - pile bearing (p. 1-36)
