Comparing Cd and Cf between ASCE 05 vs AASHTO standard spec for luminaire
Comparing Cd and Cf between ASCE 05 vs AASHTO standard spec for luminaire
(OP)
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?





