Truss Modeling

[FootNMouth]

Looking for best practices tips for modeling a long span truss. The truss will experience high point loads at panel points as well uniform loading from a composite deck. In my model should I release the moment in the truss chords at each panel point or only where a splice connection will be provided (i.e. changing section size)? In my hand calculations I have released the chords at each panel point for simplicity but when using FEA I have tried both options. For the truss with chords broken only at splice locations I am getting more moment demand which is requiring heavier sections.

 

[slickdeals]

There is enough literature that suggests that you can model trusses with pinned connections (chords and webs). In the past, I have modeled the chords to be continuous.

What is your truss composition, WT or WF chords? What kind of spans and truss depths?

 

[slickdeals]

Read this paper (

http://www.aisc.org/store/p-745-secondary-stresses-in-trusses.aspx)

There is also some commentary in Larry Muir's website (

http://www.larrymuir.com/Pages/Trusses.aspx)

 

[FootNMouth]

Thanks for the information. The chords are WF with web horizontal.