AISCAISC 360-22
Chapter J Design of connections

J7Bearing strength

PDF page 216 · AISC 360-22

The design bearing strength, ϕRn\phi R_{n}, and the allowable bearing strength, Rn/ΩR_{n} / \Omega, of surfaces in contact shall be determined for the limit state of bearing (local compressive yielding) as follows:

ϕ=0.75\phi=0.75 (LRFD) Ω=2.00\quad \Omega=2.00 (ASD)

The nominal bearing strength, RnR_{n}, shall be determined as follows:

  • (a) For finished surfaces, pins in reamed, drilled, or bored holes, bolts or rods that pass completely through an unstiffened box or HSS member, and ends of fitted bearing stiffeners
Rn=1.8FyApbR_{n}=1.8 F_{y} A_{p b}

(J7-1)

where

Apb= projected area in bearing, in. 2( mm2)Fy= specified minimum yield stress, ksi (MPa) \begin{aligned} A_{p b} & =\text { projected area in bearing, in. }^{2}\left(\mathrm{~mm}^{2}\right) \\ F_{y} & =\text { specified minimum yield stress, ksi (MPa) }\end{aligned}

  • (b) For expansion rollers and rockers
  • (1) When d25d \leq 25 in. (630 mm)
Rn=1.2(Fy13)lbd20R_{n}=\frac{1.2\left(F_{y}-13\right) l_{b} d}{20}

(J7-2)

Rn=1.2(Fy90)lbd20R_{n}=\frac{1.2\left(F_{y}-90\right) l_{b} d}{20} (J7-2M)

(2) When d>25 in. (630 mm)d>25\mathrm{~in.~}(630\mathrm{~mm})

Rn=6.0(Fy13)lbd20R_{n}=\frac{6.0(F_{y}-13)l_{b}\sqrt{d}}{20}

(J7-3)

Rn=30.2(Fy90)lbd20R_{n}=\frac{30.2(F_{y}-90)l_{b}\sqrt{d}}{20}

(J7-3M)

where d=d = diameter, in. (mm) lb=l_b = length of bearing, in. (mm)