Appendix N (Mandatory) Load and Resistance Factor A
N.2 Design Values
N.3.1 Format Conversion Factor, K F (LRFD Only)
Reference design values shall be multiplied by the format conversion factor, KF, as specified in Table N1.
Format conversion factors in Table N1 adjust reference
ASD design values (based on normal duration) to the LRFD reference resistances (see Reference 55). Format conversion factors shall not apply where LRFD refer-ence resistances are determined in accordance with the reliability normalization factor method in ASTM D 5457.
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Table N1 Format Conversion Factor, KF (LRFD Only)
Application Property KF
Member Fb
Ft
Fv, Frt Fs
Fc, Fc
Emin
2.54 2.70 2.88 2.40 1.67 1.76
All Connections (all design values) 3.32
N.3.2 Resistance Factor, (LRFD Only)
Reference design values shall be multiplied by the resistance factor, , as specified in Table N2 (see Ref-erence 55).
Table N2 Resistance Factor, (LRFD Only)
Application Property Symbol Value
Member Fb
Ft
Fv, Frt, Fs
Fc, Fc
Emin
b
t
v
c
s
0.85 0.80 0.75 0.90 0.85 All Connections (all design values) z 0.65
N.3.3 Time Effect Factor, (LRFD
Only)
Reference design values shall be multiplied by the time effect factor, , as specified in Table N3.
Table N3 Time Effect Factor, (LRFD Only)
Load Combination2
1.4D
1.2D + 1.6L + 0.5(Lr or S or R)
1.2D + 1.6(Lr or S or R) + (L or 0.5W) 1.2D + 1.0W + L + 0.5(Lr or S or R) 1.2D + 1.0E + L + 0.2S
0.9D + 1.0W 0.9D + 1.0E
0.7 when L is from storage 0.6 0.8 when L is from occupancy
1.25 when L is from impact1 0.8 1.0
1.0 1.0 1.0
1. Time effect factors, , greater than 1.0 shall not apply to connections or to structural members pressure-treated with water-borne preservatives (see Reference 30) or fire retardant chemicals.
2 Load combinations and load factors consistent with ASCE 7-10 are listed for ease of reference. Nominal loads shall be in accordance with N.1.2. D = dead load; L = live load; Lr = roof live load; S = snow load; R = rain load; W = wind load; and E = earthquake load.
REFERENCES R
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