INTRO

Question 1

Are structural elements that are subjected only to axial compressive forces; that is, the loads are applied along a longitudinal axis through the centroid of the member cross section, and the stress can be taken as f = P/A, where f is
considered to be uniform over the entire cross section

Answer 1

COMPRESSION MEMBERS

Question 2

The most common type of compression member occurring in buildings and
bridges is the (——)

A vertical member whose primary function is to support vertical loads. In many instances, these members are also subjected to bending, and in
these cases, the member is a (— —)

Answer 2

COLUMN
- beam–column

Question 3

(——- MEMBERS) are also used in trusses and as components of bracing systems.

Smaller (——-) members not classified as columns are sometimes referred to as
(—–).

Answer 3

COMPRESSION
- struts

Question 4

The AISC Specification provides for three methods of analysis to obtain THE axial forces and bending moments in members of a rigid frame:

Answer 4

1. Direct analysis method
2. Effective length method
3. First-order analysis method

Question 5

If the member buckled, what does the applied load?

Answer 5

CRITICAL BUCKLING LOAD

Question 6

For extremely stocky members, failure may
occur by (—– —) rather than buckling. Prior to failure, the compressive
stress P/A will be uniform over the cross section at any point along the length, whether
the failure is by yielding or by buckling.

Answer 6

compressive yielding

Question 7

The load at which buckling occurs is a function of (——), and for very slender members this load could be quite small.

Answer 7

slenderness

Question 8

If the member is so slender (we give a precise definition of slenderness shortly)
that the stress just before buckling is below the proportional limit—that is, the member is still (—-)

Answer 8

elastic

Question 9

The critical load is sometimes referred to as the (——-)

Answer 9

Euler load or the Euler buckling load.

Question 10

If
the stress at which buckling occurs is greater than the proportional limit of the material, the relation between stress and strain is not linear, and the modulus of elasticity
E can no longer be used

Answer 10

USED Et instead of E if cases like this

• E is not a constant for stresses
  greater than the proportional limit Fpl.

Question 11

The (——-) is defined as the slope
of the tangent to the stress–strain curve for values of f between Fpl and Fy.

Answer 11

tangent modulus Et

Question 12

(EFFECTIVE LENGTH )

Both the Euler and tangent modulus equations are based on the following assumptions:

Answer 12

1. The column is perfectly straight, with no initial crookedness.
2. The load is axial, with no eccentricity.
3. The column is pinned at both ends.

Question 13

(EFFECTIVE LENGTH)

What is the effective
length factor for the fixed-pinned compression member?

Answer 13

0.70

Question 14

(EFFECTIVE LENGTH)

What is the effective
length factor for the both ends fixed against rotation and translation, compression member?

Answer 14

k= 0.5

Question 16

( LOCAL STABILITY)

The strength corresponding to any overall buckling mode, however, such as flexural
buckling, cannot be developed if the elements of the cross section are so thin that (—- —-) occurs.

This type of instability is a localized buckling or wrinkling at an isolated location. If it occurs, the cross section is no longer fully effective, and the member has failed.

I-shaped cross sections with thin flanges or webs are susceptible to this
phenomenon, and their use should be avoided whenever possible.

Answer 16

• local
  buckling

Question 17

( LOCAL STABILITY )

For compression members, shapes are
classified as (—-) or (—-).

If a shape is slender, its strength limit state is
(— —), and the corresponding REDUCED STRENGTH must be computed.

Answer 17

• slender or nonslender
• local buckling