Chicken Wire Wind Pressure
Chicken Wire Wind Pressure
(OP)
Is anyone aware of testing done for drag coefficients for chicken wire fencing? ASCE 7 seems to agree with hand calcs based upon Reynold's number, using the width of a single wire and the opacity (% solid area) of the mesh. However, I have been warned by another engineer that it would be typical to take up to 6 times the actual profile area to account for turbulence. Much thanks...






RE: Chicken Wire Wind Pressure
We've designed lattice grids in the past where we reasoned that either the owner might someday add a nice banner to it or a large piece of plastic would blow onto it - so we designed it as a solid entity.
Otherwise...would you design for, say, 50% effective area? Just a thought.
RE: Chicken Wire Wind Pressure
RE: Chicken Wire Wind Pressure
http://www.chainlinkinfo.org/fs-architects.html
RE: Chicken Wire Wind Pressure
I would be careful about putting too much emphasis on the turbulence/supplemental drag issue. I believe those were developed with a "steady state" condition, rather than a "gust" condition. For the gust condition, a momentary large lateral deflection might be very acceptable, thus allowing a bit more range in your design.
Further, the importance factor of such a structure need not be very high. In the Florida Building Code, screen enclosures are to be designed for an importance factor of 0.77 (don't ask me why it isn't 0.75 or 0.80!).
RE: Chicken Wire Wind Pressure
One should also consider the appropriate radial ice case on the mesh. Total weight will also affect your connections.
Regards
VOD
RE: Chicken Wire Wind Pressure
RE: Chicken Wire Wind Pressure