precast78
Structural
- Aug 12, 2013
- 82
Guys,
Let's say you are analyzing a square lightpole. For AASHTO under table 3.6, it is giving us Cd value that is larger for diamond shape (wind direction 45 degree of a square x-section). That means if I analyze the pole with with 45 degree direction, not only I am making the normal area larger, but I also increase the Cf.
If you look at ASCE 05 Figure 6-21 (no section on ASCE for a pole) it is actually the other way around. If you have a square x-section and you apply wind from the corner, the Cf is lower.
Why are they not consistent? I would think the wind can blow easier trough 45 degree than perpendicular to the flat face. Am I missing something?
Let's say you are analyzing a square lightpole. For AASHTO under table 3.6, it is giving us Cd value that is larger for diamond shape (wind direction 45 degree of a square x-section). That means if I analyze the pole with with 45 degree direction, not only I am making the normal area larger, but I also increase the Cf.
If you look at ASCE 05 Figure 6-21 (no section on ASCE for a pole) it is actually the other way around. If you have a square x-section and you apply wind from the corner, the Cf is lower.
Why are they not consistent? I would think the wind can blow easier trough 45 degree than perpendicular to the flat face. Am I missing something?
