BOLTS TENSION MEMBER

S

AISC / LRFD

WILDCARD

100 100 100 100

200 200 200 200

300 300 300 300

400 400 400 400

500 500 500 500

In 2 words, what is the reason for calculation of a reduction

coefficient, U, for effective net area, Ae?

SHEAR LAG

Name the three strength limit states for tension members.

Yield of the gross cross section, net area fracture, and block

shear

What is s2/4g and how is it used?

It is a ‘length correction’ for calculation of net area when considering net area fracture

paths for staggered bolts.

For this W18x40 subject to tension, with bolted splice plates at the top

and bottom flanges, what would you use for connection eccentricity,

x?WT9x20x=2.29”

AISC Table 1-8 [p.1-61]

2.29”

USE AISC MANUAL

Which block shear path would you NOT check and why not?

#1, since the middle bolt would also have to be sheared

1

2

3

Name the recommended serviceability limit for tension

members based on ease of handling and prevention of

excessive sagging or vibration.

L / r less than or equal to 300

What is the general rule of thumb that determines

whether or not a hole can be punched?

dhole greater than tplate (or element) (often quickly check dbolt ≥ tplate)

What is the definition of ‘gage’ length?

Distance between bolts perpendicular to the direction

of loading

What is the f factor associated with fracture, what is the f

factor associated with yield, and why is one lower than the

other?0.75, 0.9, lower resistance factor results in a higher

margin of safety for brittle limit state of fracture

If Tu=120 kips, and the service load, T, is 25% dead load and

75% live load, what is the value of T?

Tu=120 kips=1.2D+1.6LL=3D

120 kips = 1.2D+1.6(3D)=6DD=20 kips

T = D + L = D + 3D = 80 kips

Bolted splice plates are typically ‘short’ with limited

inelastic deformation. Therefore, we apply this ‘rule’

in our calculations as an additional factor of safety:

The “85% rule”Ae = An ≤ 0.85 Ag

AISC J4.1

In this equation for capacity of a tension rod or bolts in tension, one 0.75 is the

resistance factor; what is the purpose of the other 0.75?

The other 0.75 accounts for the reduced cross-sectional area of the

threaded portion.

bun AFT )75.0(75.0

Why does the equation for bearing capacity of a bolt include Fu of the plate or

connected part?

Derivation of the bearing resistance equations considers

splitting failure of the plate

What are the workable gage

distances for this L8x4x1/2 with 2 bolts in the long leg and 1 bolt in the short leg?

3”, 3” and 2-1/2”AISC Table 1-7A

2-1/2”

3”

3”

USE AISC MANUAL

In the above equation for shear of bolts with threads excluded, the 0.563 includes a 0.625 for

shear and a 0.9 for what?

Connection length effect

0.75(0.563 )bn u bR F mA

If bolts are used in combination with welds, they should be

designed as slip critical. Why? The bolts will not bear on the plate

unless welds have failed and the bolts can slip. Therefore, the design should be based on the bolts’ slip-critical capacity,

rather than bearing-type (shear and bearing) capacity.

In this equation for slip-critical connections, the resistance factor, f, varies depending

upon what?Hole type (e.g., standard, oversized, short- or long-

slotted)

n u f b sR D hT n

In the AISC Spec., the minimum

edge distance, Le, depends on

what?

The diameter of bolt (AISC Table J3.4)

Le

For A325N bolts in bearing-type connections subject to

combined shear and tension, the tensile stress demand must

be less than the available tensile strength, fF’nt, which

also must be less than or equal to ___?f0.75 Fu

b = (0.75)(0.75)120 ksi=67.5 ksi

Even though the upper limit on the block shear limit state

includes a rupture component and a yield component, it is

primarily a rupture limit state. Therefore, the f factor is ___?

0.75