HSS Vierendeel Truss Conxns

[WAstruc10]

I have a vierendeel truss comprised of round hss chords and web members (for visualization purposes, say all 12" o.d.). Each web/chord connection must obviously transfer a combination of axial, bending, and shear stresses. Each chord will be continuous, with the web pipes cut to the required curvature to "straddle" the chord pipe (as with standard truss connections which I've seen designed for axial only). My question is how to analyze the combined stresses at the "roller-coaster-shaped" weld between members? This must consider not only the strength of the weld but the crushing forces in the wall of the chord pipe. Thanks!

 

[trainguy]

Try Design Guide for Hollow Structural Section Connections by Packer and Henderson (Canadian Institute of Steel Construction). There's plenty on truss joint design, although I'm not sure they have round members.

 

[WAstruc10]

Thanks trainguy. I don't have access to that one, but I wonder if it isn't similar to the AISC HSS Conxns Manual. I would consider this book the industry standard as far as HSS are concerned, but they only deal with "typical" tube-to-tube truss connections (i.e. axial loads only as if pinned ends, warren truss used as example). Nothing that simultaneously considers end moments (not vierendeel-friendly).

 

[trainguy]

Sounds like you should do an FEA of a typical joint, making sure to include all the forces/moments from the adjacent structure. I think the book I suggested is probably very much like the AISC reference you mention.

tg

 

[WAstruc10]

Yeah, I was hoping to get out of that...such is life I suppose.

 

[SmithJ]

Hello,

Apologies in advance but I would like to field a question. I am about to use HSS tubes (4x4x3/16) as X-bracing in a large arena. Would you consider it necessary to consider eccentricity in the bolted connections to the columns/beams?

AISC Volume II seems to ignore this eccentricity in all their connection examples and I am not clear if this is considered indusstry standard.

Thanks in Advance.

JS.