Description of Element
Case Shear Lag Factor, U Example
1
2
3
4
5
6
7
8
All tension members where the tension load is transmitted directly to each of the cross-sectional elements by fasteners or welds (except as in Cases 4, 5 and 6).
All tension members, except plates and HSS, where the tension load is trans- mitted to some but not all of the cross- sectional elements by fasteners or longitu- dinal welds or by longitudinal welds in combination with transverse welds. (Alter- natively, for W, M, S and HP, Case 7 may be used. For angles, Case 8 may be used.) All tension members where the tension load is transmitted only by transverse welds to some but not all of the cross-sectional elements.
Plates where the tension load is transmitted by longitudinal welds only.
Round HSS with a single concentric gusset plate
Rectangular HSS with a single concentric gusset plate
with two side gusset plates
W, M, S or HP Shapes or Tees cut from these shapes.
(If Uis calculated per Case 2, the larger value is per- mitted to be used.)
Single and double angles (If Uis calculated per Case 2, the larger value is permitted to be used.)
U=1.0
U=0.70
U=0.80
U=0.60
U x
= −1 l
U=1.0 and
An=area of the directly connected elements
/ ≥2w…U=1.0 2w> /≥1.5w…U=0.87
1.5w> /≥w…U=0.75
bf≥2/3d…U=0.90 bf<2/3d…U=0.85 / ≥1.3D…U=1.0
D l D U x
≤ <1 3. … = −1 l x= πD
l H U x
≥ … = −1 l
l H U x
≥ … = −1 l
x B BH
= B H+ + 2 2
4( )
x B
= B H+ 2
4( )
with flange con- nected with 3 or more fasteners per line in the direction of loading
with web connected with 4 or more fas- teners per line in the direction of loading with 4 or more fas- teners per line in the direction of loading with 3 fasteners per line in the direction of loading (With fewer than 3 fasten- ers per line in the direction of loading, use Case 2.)
l=length of connection, in. (mm); w=plate width, in. (mm); x–=eccentricity of connection, in. (mm); B=overall width of rectangular HSS member, measured 90° to the plane of the connection, in. (mm); H=overall height of rectangular HSS member, measured in the plane of the connection, in. (mm)
D5. PIN-CONNECTED MEMBERS 1. Tensile Strength
The design tensile strength, φtPn, and the allowable tensile strength, Pn/Ωt, of pin- connected members, shall be the lower value determined according to the limit states of tensile rupture, shear rupture, bearingand yielding.
(a) For tensile rupture on the net effective area:
Pn=Fu(2tbe) (D5-1)
φt=0.75 (LRFD) Ωt=2.00 (ASD) (b) For shear rupture on the effective area:
Pn=0.6FuAsf (D5-2)
φsf=0.75 (LRFD) Ωsf=2.00 (ASD) where
Asf =area on the shear failure path =2t(a+d/ 2), in.2 (mm2)
a =shortest distance from edge of the pin hole to the edge of the member measured parallel to the direction of the force, in. (mm)
be =2t+0.63, in. (=2t+16, mm), but not more than the actual distance from the edge of the hole to the edge of the part measured in the direction nor- mal to the applied force, in. (mm)
d =diameter of pin, in. (mm) t =thickness of plate, in. (mm)
(c) For bearing on the projected area of the pin, use Section J7.
(d) For yielding on the gross section, use Section D2(a).
2. Dimensional Requirements
The pin hole shall be located midway between the edges of the member in the direc- tion normal to the applied force. When the pin is expected to provide for relative movement between connected parts while under full load, the diameter of the pin hole shall not be more than 1/32in. (1 mm) greater than the diameter of the pin.
The width of the plate at the pin hole shall not be less than 2be+dand the minimum extension, a, beyond the bearingend of the pin hole, parallel to the axis of the mem- ber, shall not be less than 1.33be.
The corners beyond the pin hole are permitted to be cut at 45° to the axis of the member, provided the net areabeyond the pin hole, on a plane perpendicular to the cut, is not less than that required beyond the pin hole parallel to the axis of the member.
D6. EYEBARS 1. Tensile Strength
The available tensile strength of eyebars shall be determined in accordance with Section D2, with Agtaken as the cross-sectional area of the body.
For calculation purposes, the width of the body of the eyebars shall not exceed eight times its thickness.
2. Dimensional Requirements
Eyebars shall be of uniform thickness, without reinforcement at the pin holes, and have circular heads with the periphery concentric with the pin hole.
The radius of transition between the circular head and the eyebar body shall not be less than the head diameter.
The pin diameter shall not be less than seven-eighths times the eyebar body width, and the pin hole diameter shall not be more than 1/32in. (1 mm) greater than the pin diameter.
For steels having Fygreater than 70 ksi (485 MPa), the hole diameter shall not exceed five times the plate thickness, and the width of the eyebar body shall be reduced accordingly.
A thickness of less than 1/2 in. (13 mm) is permissible only if external nuts are pro- vided to tighten pin plates and fillerplates into snug contact. The width from the hole edge to the plate edge perpendicular to the direction of applied loadshall be greater than two-thirds and, for the purpose of calculation, not more than three-fourths times the eyebar body width.