Gust Factor for Flexible Structures: ASCE 7-10 Section 26.9.5

[ENGINEER92]

I am creating an excel sheet for calculating the Gust Factor for flexible structures. I have found a video online discussing wind loads on non building structures and in the video they calculate the gust factor for a flexible structure. They do not show all their calculations but they do give me their given and their final gust factor. I am using this video to check my excel sheet and I am not able to get the same answer that they do. I have gone through my excel sheet multiple times and I cannot find any errors in it. I would appreciate if anyone else could tell me for these given values what gust factor do you get. Thank you before hand on any replies.

Given:
n1=.773 Hz
Exposure Category=C
B=10 ft
L=10 ft
h= 97.5 ft
V=120 mph
B=damping ratio=.05

Required:
Calculate gust factor for flexible structures for ASCE 7-10 section 26.9.5.

Solution:
Answer in video Gf=1.272
Answer I am getting Gf=.968

 

[MrHershey]

My sheet also yields 0.968 for those numbers.

 

[ENGINEER92]

Thank you MrHershey for the reply. That is reassuring to hear you are getting the same thing.

 

[UcfSE]

Same here, 0.968. On another note, a damping ratio of 5% for wind is very high. Is that just for checking your spreadsheet?

 

[ENGINEER92]

Yes, I am just checking my spreadsheet. These values are not from any project I am working on.

 

[JAE]

I am getting 0.968 also on our spreadsheet.

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[iv63]

ENGINEER92, can you please share that online video?
iv

 

[ENGINEER92]

https://www.youtube.com/watch?v=B1B5UcLK0W0

The video was done by RISA, it gives an example of how to model a non building structure in their program. They do a good job on showing their work on how they got their wind loads.