MIDTERM EXAM

Question 1

The actual rupture strength of a plastic material is greater than the ultimate tensile strength if
we consider the reduce area due to

Answer 1

Necking

Question 2

Strain hardening is the result of dislocation or ____________ of the metal crystals.

Answer 2

Movement

Question 3

Values for factor of safety in ASD is based on

Answer 3

all of the above

Question 4

LRFD is limited to inelastic behaviour

Answer 4

True

Question 5

Strength Limit State is to collapse prevention as Serviceability Limit State is to

Answer 5

Function

Question 6

Which of the following statement represents failure

Answer 6

none of the above

Question 7

ASD differ primarily with LRFD with in providing

Answer 7

Safety Factors

Question 8

ASD is all about allowable stresses

Answer 8

True

Question 9

What is the factor of safety for Tension Members in LRFD considering the combination U=1.4D

Answer 9

1.56

Question 10

For high strength steel the plastic strain increases because of the increase on the ultimate
strength

Answer 10

False

Question 11

The limit state is the dividing between failure an

Answer 11

Survival

Question 12

LRFD is all about allowable loads

Answer 12

False

Question 13

Reliability index is the number of times the measure of the variance is to the mean from the
origin

Answer 13

False

Question 14

By how many percent is LRFD cheaper for a Tension Member Design compared to ASD if L/D=1

Answer 14

6

Question 15

In ASD the values of the coefficient on the Load Combinations are not based on probabilities.
(T/F)

Answer 15

T

Question 16

Flexural Torsional Buckling is more commonly known as ___________ in beams.

Answer 16

lateral torsional buckling

Question 17

Cc is a dimensionless parameter for slenderness in ASD (T/F)

Answer 17

TRUE

Question 18

Flexural buckling limit states includes elastic, inelastic and_________

Answer 18

Yielding

Question 19

When the actual width to thickness ratio is less than the limiting value set forth on the code,
then the column will not experience ___________________________.

Answer 19

Local buckling

Question 20

Given: Fy=100ksi
Determine the slenderness ratio kl/r when Fcr=(2/3)Fy at the end of pure elastic stage.

Answer 20

65.5

Question 21

How many stiffened section does a HSS rectangular section has?

Answer 21

4

Question 22

The slender limits for stiffened element local buckling is always greater than the slenderness
limits for unstiffened local buckling. (T/F)

Answer 22

T

Question 23

Which of the shapes is more vulnerable to lateral-torsional buckling?

Answer 23

unequal angle

Question 24

Slenderness ratio is measured by dividing ______________ over radius of gyration

Answer 24

effective length

Question 25

Shanley concept introduces the critical load at which buckling begins and this is less the critical load of Engesser. (T/F)

Answer 25

FALSE

Question 26

The reason for a transition curve in between the elastic and plastic stage for a column behavior is mainly attributed to

Answer 26

Residual Stress

Question 27

Residual stress are compressive where the rate of cooling is fast. (T/F)

Answer 27

true

Question 28

Given: See Figure Question 11. Fy=100ksi Determine the slenderness ratio kl/r when all the fibers become plastic.

Answer 28

18.9

Question 29

The limiting width to thickness ratio λr of a plate element subject to compression force is called

Answer 29

non-compact limit

Question 30

How many unstiffened element does a wide flange section has?

Answer 30

4

Question 31

Flame cutting of steel plates introduces compressive stresses at the points of cutting. (T/F)

Answer 31

FALSE

Question 32

Given: See Figure Question 11. Fy=100ksi What is the value of tangent modulus at the transition stage.

Answer 32

(1/8)E

Question 33

Shape factors Q for slender elements is less than 1 while shape factors Q for non-slender elements is ___________.

Answer 33

equal to 1

Question 34

Weak axis buckling is critical for columns under

Answer 34

axial compressive load only

Question 35

Given: See Figure Question 11. Fy=100ksi Determine the slenderness ratio kl/r if there where no residual stress.

Answer 35

53.5

Question 36

How many number of support does an unstiffened element has which makes it less stable than a stiffened element.

Answer 36

1

Question 37

Built up shapes are more stable than rolled shapes in terms of local buckling.

Answer 37

False

Question 38

For local buckling failure on columns, the element subject to local loads must experience

Answer 38

uniform compression

Question 39

The local shape factor Qs for is based on average stress developed in the plate element while the local shape factor Qa is based on ___________________.

Answer 39

effective length

Question 40

λc is a dimensionless parameter representing the LRFD parameter for

Answer 40

slenderness

Question 41

Given: See Figure Question 11. Fy=100ksi Determine the slenderness ratio kl/r when Fcr=(2/3)Fy at the elasto plastic stage.

Answer 41

23.2

Question 42

Residual stresses are tensile at the joints but not at the free end. (T/F)

Answer 42

TRUE

Question 43

The point of load application at which no torsional behavior is induced in the member is called

Answer 43

none of the above

Question 44

Inelastic column buckling is common for long, slender columns. (T/F)

Answer 44

FALSE

Question 45

Which of the shapes is more vulnerable to pure torsion?

Answer 45

Cruciform