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BOLTS TENSION MEMBERS AISC / LRFD WILD CARD 100 200 300 400 500

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In 2 words, what is the reason for calculation of a reduction coefficient, U, for effective net area, Ae? SHEAR LAG

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**Name the three strength limit states for tension members.**

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

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**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.

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**WT9x20 x=2.29” AISC Table 1-8 [p.1-61]**

For this W18x40 subject to tension, with bolted splice plates at the top and bottom flanges, what would you use for connection eccentricity, x? 2.29” WT9x20 x=2.29” AISC Table 1-8 [p.1-61] USE AISC MANUAL

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

1 2 3 Which block shear path would you NOT check and why not? #1, since the middle bolt would also have to be sheared

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**L / r less than or equal to 300**

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

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**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)

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**What is the definition of ‘gage’ length?**

Distance between bolts perpendicular to the direction of loading

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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

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**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+1.6L L=3D 120 kips = 1.2D+1.6(3D)=6D D=20 kips T = D + L = D + 3D = 80 kips

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**The “85% rule” Ae = An ≤ 0.85 Ag AISC J4.1**

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

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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.

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**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

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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” 2-1/2” 3”, 3” and 2-1/2” AISC Table 1-7A USE AISC MANUAL

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**Connection length effect**

In the above equation for shear of bolts with threads excluded, the includes a for shear and a 0.9 for what? Connection length effect

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**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.

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**Hole type (e.g., standard, oversized, short- or long-slotted)**

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)

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**In the AISC Spec., the minimum edge distance, Le, depends on what?**

The diameter of bolt (AISC Table J3.4)

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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 Fub = (0.75)(0.75)120 ksi =67.5 ksi

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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

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