52

- 2.4fv < 45

a For the LSD method, see appendix B of the AISI North American Specification [7].

Note: d is the nominal diameter of bolt and f is the shear stress based on gross cross-sectional area of bolt; 1 in. = 25.4 mm, 1 ksi = 6.9 MPa = 70.3 kg/cm2.

TABLE 6.11 Nominal Strength Equations for Screws

Type of strength Nominal strength

Shear strength

1. Connection shear limited by tilting and bearing For t2/t1 < 1.0, use smallest of three considerations

For t2/t1 > 2.5, use smallest of two considerations

For 1.0 < t2/t1 < 2.5, use linear interpolation

2. Connection shear limited by end distance

3. Shear in screws Tensile strength

1. Connection tension Pull-out strength Pull-over strength

2. Tension in screws a For the LSD method see appendix B of the AISI North American Specification [7].

Note: d is the nominal diameter of screw, dw is the larger of screw head diameter and washer diameter, Fu1 is the tensile strength of member in contact with the screw head (Figure 6.38), Fu2 is the tensile strength of member not in contact with the screw head (Figure 6.37), Pns is the nominal shear strength per screw, Pss is the nominal shear strength per screw as reported by the manufacturer or determined by tests, Pnt is the nominal tension strength per screw, Pnot is the nominal pull-out strength per screw, Pnov is the nominal pull-over strength per screw, Pts is the nominal tension strength per screw as reported by the manufacturer or determined by tests, t1 is the thickness of member in contact with the screw head (Figure 6.38), t2 is the thickness of member not in contact with the screw head (Figure 6.37), and tc is the lesser of depth penetration and thickness t2.

6.8.1 Metal Buildings

Standardized metal buildings have been widely used in industrial, commercial, and agricultural applications. This type of metal building has also been used for community facilities because of

0 0

Post a comment