NDS load duration factor CD for wind load.

[NGA]

I am looking for the information of load duration factor CD for the wind load. I don’t have NDS at my hands. I find this factor in UBC 1997 is 1.33 with the foot note saying that 1.60 may be used for members and nailed and bolted connections exhibiting Mode III or IV behavior. Is it the same as in NDS? Also I would like to have more background information about this load duration factor when the number 1.60 is used and what is the Mode III or IV behavior. Any help from you will be greatly appreciated.



Luke

RSD Engineering, PC

212-324-9900

 

[JAE]

NDS 1997 only uses 1.60 for transient wind loads. There is no mention of 1.33.