(0.347 k ) 2
= 0.245k /brace (1.09KN/brace)
Pu =
2
Dead load per brace;
(0.619 k ) 2
= 0.438k/ brace (1.99KN/brace)
Pu =
2
Load combinations;
Pu = 1.4(0.438k/brace) = 0.61k/brace (2.71KN/brace)
U = 1.4D;
Pu = 1.2(0.438k/brace) + 0.245k/brace = 0.77k/brace (3.42KN/brace)
U = 1.2D + E;
Pu = 0.9(0.438k/brace) 0.245k/brace = 0.15k/brace (0.67KN/brace)
U = 0.9D E;
At location S2;
Seismic load per brace;
(0.526k ) 2
= 0.372 k /brace (1.65KN/brace)
Pu =
2
Dead load per brace;
(0.939 k ) 2
= 0.664 k /brace (2.95KN/brace)
Pu =
2
Load combinations;
Pu = 1.4(0.664k/brace) = 0.93k/brace (4.14KN/brace)
U = 1.4D;
Pu = 1.2(0.664k/brace) + 0.372k/brace = 1.17k/brace (5.20KN/brace) (governs)
U = 1.2D + E;
Pu = 0.9(0.664k/brace) 0.372k/brace = 0.23k/brace (1.02KN/brace)
U = 0.9D E;
At location S3;
Note: No dead load acts at location S3.
Seismic load per brace;
(0.356k ) 2
= 0.25k /brace (1.11KN/brace)
Pu =
2
Load combinations;
Pu = 0.25k/brace (1.11KN/brace)
U = E;
Note: Braces always act in tension.
Check capacity of angle braces;
Check yielding on the gross area;
φt Pn = 0.90Fy A g = 0.9(36ksi)0.715 - in2 = 23.2 k > 1.17 k = Pu (103.2KN > 5.20KN)
O.K.
Check fracture on the effective net area;
φt Pn = 0.75FuA e = 0.75(58ksi)0.281 - in2 = 12.2 k > 1.17 k = Pu (54.3KN > 5.20KN)
O.K.
Use 2-L2x2x3/16 (2-L50.8mmX50.8mmX4.8mm) braces
Design connections to pipe;
Determine design loads;
1.17 k /brace
= 0.83k/connection
Tu = Vu =
(3.69KN/connection)
2
Try a single 3/8" φA307 bolt in a bearing type connection;
Check shear;
φ n = φ nA b
where; φt = 0.75
R
F
(per AISC LRFD section J3.6)
Fn = 24ksi
(per AISC LRFD Table J3.2)
π(3 / 8" ) 2
= 0.11 - in2 (71.0mm2)
Ab =
4
φ n = φ nA b = 0.75(24ksi)0.11 - in2 = 1.98k > 0.83k = Vu (8.81KN > 3.69KN)
O.K.
R
F
Check bearing;
By inspection, Le > 1.5d;
J3-5
Previous Page
