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3. Related Code in AISC 13th ed Specifications.

3.1. Nominal Shear Stress of bolts in bearing type of connection

3.2. Bearing strength at bolt holes (AISC 13th ed. Section J3.10)

3.3 Shear strength of member in connection (AISC 13th ed. section J3.2)

3.4. Block shear strength (AISC 13th ed. Section J3.3)

3.5 Normal tensile strength of bolts in bearing type of connection

3.6 Available tensile strength of a bolt subject to tension and shear in bearing-type connections

4. LRFD design example

5. ASD design example

LRFD design:

- R
_{u}£ fR_{n}.

Where R_{u} is
factored shear force calculated based on strength design provision
of building code. R_{n} is nominal
shear strength calculated based on AISC 13th ed, f is
resistance factor.

- R £ R
_{n}/W.

Where R_{ }is
service load force calculated based on allowable stress design
provision of building code, R_{n} is
normal shear strength calculated based on AISC 13th edition, W
= is safety factor.

1. Determine number of bolt based on bolt shear in connecting beam

2. Check number of bolt in supporting beam for shear and tension due to eccentricy.

3. Check bolt bearing on beam web.

4. Check shear strength of beam web.

5. Check block shear of beam web.

6. Check bolt bearing of connection angle.

7. Check gross shear of connection angle.

8. Check block shear of connection angle.

Resistance factor: f = 0.75 (LRFD)

Safety factor: W = 2.0 (ASD)

Nominal Shear strength

R_{n} = F_{nv} A_{b}

Where A_{b} is
nominal unthreaded body area of bolt, F_{nv} is
shown below from AISC 13th ed. TableJ3.2.

Nominal shear stress | |

A307 bolt | 24 |

A325-N, A325M-N bolts, (threads are not excluded from shear plans) | 48 |

A325-X, A325M-X bolts, (threads are excluded from shear plans) | 60 |

A490-N, A490M-N bolts, (threads are not excluded from shear plans) | 60 |

A490-X, A490M-X bolts, (threads are excluded from shear plans) | 75 |

Resistance factor: f = 0.75 (LRFD)

Safety factor: W = 2.0 (ASD)

Nominal bearing strength of bolt holes

a. When deformation at the bolt hole at service load is a design consideration

R_{n} = 1.2 L_{c} t
F_{u} £
2.4 d t F_{u}

b. When deformation at the bolt hole at service load is not a design consideration

R_{n} = 1.5 L_{c} t
F_{u} £
3 d t F_{u}

c. The bearing resistance shall be taken as the sum of the bearing resistance of the individual bolts.

Where d is bolt diameter, t is thickness of the member, F_{u} is
tensile stress of connection material

L_{c} is clear
distance, in the direction of the force, between edge of holes or
edge of hole to edge of material.

a. Shear yielding of beam web

Resistance factor: f = 1.0 (LRFD)

Safety factor: W = 1.5 (ASD)

R_{n} = 0.6 F_{y} A_{g}

Where F_{y} is
yield strength of material, Ag is gross area subject to shear.

b. Shear rupture of beam web

Resistance factor: f = 0.75 (LRFD)

Safety factor: W = 2 (ASD)

R_{n} = 0.6 F_{u} A_{nv}

Where F_{u} is
minimum tensile strength of material, A_{nv} is
net area subject to shear.

Resistance factor: f = 0.75 (LRFD)

Safety factor: W = 2.0 (ASD)

R_{n} = 0.6 F_{u} A_{nv} +
U_{bs} F_{u} A_{nt} £
0.6 F_{y} A_{gv} +
U_{bs} F_{u} A_{nt}

A_{gv} is gross
area subject to shear

A_{nt} is net
area subject to tension

A_{nv} is net
area subject to shear

Ubs = 1 for if only one column of bolt is used., Ubs = 0.5 for more than one column of bolt is used.

Resistance factor: f = 0.75 (LRFD)

Safety factor: W = 2.0 (ASD)

Nominal tensile strength

R_{n} = F_{nt} A_{b}

Where A_{b} is
nominal unthreaded body area of bolt, F_{nt} is
shown below from AISC 13th ed. TableJ3.2.

Nominal tensile stress | |

A307 bolt | 45 |

A325-N, A325M-N bolts, (threads are not excluded from shear plans) | 90 |

A325-X, A325M-X bolts, (threads are excluded from shear plans) | 90 |

A490-N, A490M-N bolts, (threads are not excluded from shear plans) | 113 |

A490-X, A490M-X bolts, (threads are excluded from shear plans) | 113 |

Resistance factor: f = 0.75 (LRFD)

Safety factor: W = 2.0 (ASD)

Available tensile strength

R_{n} = F'_{nt} A_{b}

Where A_{b} is
nominal unthreaded body area of bolt, F'_{nt} is
calculated as

F'_{nt} = 1.3 F_{nt} -
[F_{nt}/fF_{nv}]f_{v} £
F_{nt} (LRFD)

F'_{nt} = 1.3 F_{nt} -
[WF_{nt}/F_{nv}]f_{v} £
F_{nt} (ASD)

where f_{v} is
required shear stress, ksi.