| Select a sawn timber member to carry a permanent axial compressive load of 12 kN |
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N*c = |
12 |
kN |
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| say the column is 2.4m long and restrained about the strong axis at the ends, |
| restrained about the weak axis @0.8 crs |
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| Using MSG8 timber, actual size of 100x50 is 90x45 |
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d = |
90 |
mm |
b = |
45 |
mm |
| need to satisfy: |
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N*c <= fNncx |
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| and |
N*c <= fNncy |
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| about the strong axis x-x |
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k10. L = |
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2400 |
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S2 = k10.L/d or Lax / d= |
26.7 |
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k8 = |
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0.41 |
from NZS3603 2.10 |
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| about the weak axis y-y |
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Lay = |
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800 |
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S3 = k10.L/d or Lay / d= |
17.8 |
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k8 = |
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0.78 |
from NZS3603 2.10 |
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fc = |
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18 |
MPa |
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k1 = |
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0.6 |
for a permanent load |
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f = |
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0.8 |
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fNncx = f.k1.k8.fc.A = |
14.3 |
kN |
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fNncy = f.k1.k8.fc.A = |
27.2 |
kN |
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Example prepared by David Reid, Structural Engineer. |
