Top Chord member selection...
Top Chord member selection...
(OP)
Working on a truss and viewing the different methods for accurate analysis, there is no shear and moment diagrams for them. Why? When digging into the AISC construction manual to find an appropriate member, its simply a compression property that we look into? For example, I have a truss that spans 127 ft. with a tributary width of 47 ft. A simple DL of 25 and LL of 20. I can not reduce the Live Load because its an assembly structure and in doing a traditional moment and shear diagram then my results are huge. Finding a member that can hold a 1,771 kip ft. moment is crazy. If I look for a compression property(Table4-7), bases on my method of joint and section analysis, well then my selections are very reasonable such as a WT12x52 could do the trick.
How do you guys go about selecting the members.
Thank you,
Hemi79
How do you guys go about selecting the members.
Thank you,
Hemi79





RE: Top Chord member selection...
The development of computer programs such as RISA 3D computes what these moments are too, as well as moments and shears along set points of the member's length if needed.
If you are not well versed in the design of trusses, you really should engage a structural engineer to help you. They can be pretty specialized, especially at the span you are talking about.
Mike McCann
MMC Engineering
RE: Top Chord member selection...