PURLINS & GIRTS

SECTIONAL PROPERTIES
PURLIN
SIZE
AREA WEIGHT
SECOND MOMENT OF AREA
(GROSS SECTION)
SECTION MODULUS
RADIUS OF GYRATION
TORSION WARPING
CONSTANT FACTOR
A s W t I x I y Z x Z y r x r y J I w
HST MM 2 KN/M 10 6 MM 4 10 6 MM 4 10 3 MM 3 10 3 MM 3 MM MM MM 4 10 9 MM 6
100/12 253 0.019 0.423 0.092 8.38 2.78 40.9 19.1 111 0.21
100/15 316 0.024 0.525 0.114 10.45 3.44 40.8 18.9 222 0.26
100/19 400 0.031 0.658 0.141 13.14 4.29 40.6 18.7 456 0.31
150/12 386 0.030 1.38 0.249 18.1 6.14 59.8 25.4 170 1.54
150/15 483 0.037 1.72 0.308 22.6 7.61 59.7 25.2 338 1.87
150/18 578 0.044 2.05 0.364 27.0 9.01 59.6 25.1 590 2.19
200/12 478 0.037 3.00 0.392 29.6 8.04 79.2 28.6 211 3.93
200/15 598 0.046 3.75 0.486 36.9 9.98 79.2 28.5 419 4.83
200/18 717 0.055 4.48 0.577 44.2 11.90 79.1 28.4 732 5.67
250/13 625 0.048 5.85 0.655 46.8 11.90 96.8 32.4 325 10.4
250/15 722 0.056 6.76 0.753 54.0 13.7 96.7 32.3 506 11.9
250/18 866 0.067 8.09 0.897 64.7 16.3 96.6 32.2 885 14.0
300/15 847 0.065 11.5 1.23 76.4 18.5 116 38.1 594 26.4
300/18 1018 0.078 13.7 1.46 91.6 22 116 37.9 1039 31.2
300/24 1382 0.106 18.6 1.95 124 29.5 116 37.6 2653 41.1
300/30 1711 0.132 22.9 2.38 153 36.0 116 37.3 5134 49.4
350/18 1123 0.086 20.1 1.63 115 24 134 38.1 1146 46.7
350/24 1526 0.117 27.2 2.17 155 32.1 133 37.7 2930 61.6
350/30 1891 0.146 33.5 2.65 192 39.3 133 37.4 5674 74.3
400/20 1365 0.105 31.1 1.97 155 28.6 151 38.0 1730 73.1
400/24 1670 0.128 37.9 2.39 190 34.7 151 37.8 3206 87.7
400/30 2071 0.159 46.9 2.92 234 42.5 150 37.5 6214 106
Note: All section properties are for the gross section.
SECTION CAPACITIES
PURLIN
SIZE
SECTION
MOMENT
CAPACITY
DISTORTIONAL
BUCKLING
MOMENT
CAPACITY
FLEXI-TORSIONAL BUCKLING MOMENT CAPACITY φ b M fb x
EFFECTIVE LENGTH (LE) IN METRES
(kN.m)
SHEAR
CAPACITY
AXIAL
COMPRESSION
SECTION
CAPACITY
HST φ b M sx φ b M dbx 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 φ v V v φ c N s
(kN.m) (kN.m)
(kN)
(kN)
150/12 7.0 6.0 5.7 3.7 2.2 1.5 1.0 0.8 0.6 0.5 0.4 0.4 0.3 13.7 125.7
150/15 9.7 8.2 7.8 4.9 2.8 1.9 1.3 1.0 0.8 0.7 0.6 0.5 0.4 26.2 176.6
150/18 11.2 9.7 9.2 5.8 3.4 2.3 1.6 1.3 1.0 0.8 0.7 0.6 0.6 44.4 212.4
200/12 10.9 8.7 9.3 6.7 4.2 2.9 2.0 1.5 1.2 0.9 0.8 0.6 0.6 10.7 142.0
200/15 15.0 12.0 12.8 9.1 5.5 3.6 2.5 1.9 1.5 1.2 1.0 0.8 0.7 20.3 201.5
200/18 17.6 14.4 15.2 11.2 6.6 4.3 3.1 2.3 1.8 1.5 1.3 1.1 0.9 34.2 246.2
250/13 17.2 13.5 15.5 12.5 8.4 5.7 4.1 3.1 2.4 1.9 1.6 1.3 1.1 12.3 176.4
250/15 21.3 16.5 19.0 15.3 10.0 6.8 4.8 3.6 2.8 2.2 1.8 1.5 1.3 18.4 224.4
250/18 25.0 20.0 22.6 18.4 12.5 8.2 5.8 4.3 3.4 2.7 2.2 1.9 1.6 30.7 277.4
300/15 26.2 20.2 24.7 21.7 17.2 11.9 8.7 6.6 5.1 4.1 3.3 2.8 2.4 14.9 218.7
300/18 34.0 26.1 31.9 27.7 21.6 14.9 10.8 8.0 6.2 4.9 4.0 3.4 2.9 24.8 296.0
300/24 49.8 39.9 46.7 40.3 31.2 20.8 14.6 10.9 8.5 6.8 5.7 4.8 4.1 59.1 476.3
300/30 64.0 53.5 59.9 51.6 38.7 25.6 18.2 13.7 10.7 8.7 7.3 6.2 5.4 109.9 642.8
350/18 41.6 31.7 39.2 34.5 27.6 19.1 13.8 10.2 7.9 6.3 5.1 4.3 3.6 20.7 320.5
350/24 62.7 48.6 59.0 51.1 39.9 26.6 18.7 13.9 10.8 8.6 7.1 6.0 5.1 49.6 525.3
350/30 81.3 65.3 76.3 65.2 49.4 32.7 23.1 17.3 13.5 10.9 9.0 7.6 6.6 92.3 706.7
400/20 58.5 43.1 55.2 48.5 38.7 26.9 19.1 14.1 10.9 8.6 7.1 5.9 5.0 24.0 369.2
400/24 76.2 57.1 71.8 62.6 49.4 33.1 23.2 17.2 13.3 10.6 8.7 7.3 6.2 42.6 504.6
400/30 99.6 77.0 93.6 80.3 61.2 40.7 28.6 21.3 16.6 13.3 11.0 9.3 7.9 79.4 688.9
Notes:
1. φ b M sx – Design section moment capacity about X axis.
2. φ b M dbx – Design member moment capacity about X axis subject to distortional buckling.
3. φ b M fb x – Design member moment capacity about X axis subject to lateral buckling. Values are based on the moment distribution of a uniform
moment over entire unbraced segment at the centroid of HST. Refer to AS/NZS 4600:2005 for the values of other moment distributions.
No sheeting restraint has been considered in the calculation.
4. φ v V v – Design shear capacity of HST webs without service holes.
5. φ c N s – Design section capacity of the member in axial compression.
6. The table should be used in conjunction with AS/NZS 4600:2005.
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