Bolt Shear and Bearing

ϕ r_{n}^{shear} = ϕ F_{n v} A_{b}, ϕ r_{n}^{bear} = ϕ 1.2 F_{u} d t (when deformation is a consideration)

Count shear planes (single/double). Bearing on the plate uses Fu, d, t and edge distance (1.2 vs 2.4 Fu dt). Block shear is a separate path. Threads included or excluded change Fnv.

$F n v$: Nominal shear stress of the bolt
$F u$: Tensile strength of the plate
$t$: Ply thickness

Step-by-step solved example

¾ in A325-N, Fnv=48 ksi, one plane, φ=0.75. φrn shear?

Bolt group: shear planes and plate bearing P/(d t).

1. Ab
π(0.75)²/4=0.442 in².
2. φrn
0.75×48×0.442=15.9 kip.

Answer: φrn ≈ 16 kip / bolt in single shear

10 practice questions

0/10 correct

1.Double shear doubles

2.Bearing 1.2 Fu d t vs 2.4 is

3.Threads excluded (X) have

4.Minimum edge distance is in the

5.Block shear φRn combines

6.Ab of a 1 in bolt is

7.Slip-critical bolts are designed for

8.Fu=58 ksi, d=0.75, t=0.375, 1.2 Fu d t =

9.A bolt group eccentric in-plane uses

10.φ for bolt shear (LRFD) is typically