Through Plate Strengthing CHS 1

[ahmedhegazi]

i have a truss formed out of CHS (Circular Hollow Section) where diagonal members are welded to Chord ,after checking the limits as per AISC chapter K ,found that joint require strengthening as Chord Plastification capacity is less than diagonal force .

what would be easier for fabricator is to reinforce the joint using through plate welded to both sides of chord ,however for Architectural reasons the Diagonal members should be also direct welded to the Chord . does anyone have design guides for these type of reinforced connection?

 

[ishvaaag]

I don't have for circular chord, but there is some guide for rectangular.

Have a mathcad worksheet for that, based I think on the attached article, will post later.

 

[ishvaaag]

The mathcad 2000 professional worksheet.

 

[ishvaaag]

Due to the circular section the evaluated values as a close rectangular section should be safe, since embraced by the weld of the lesser members to the chord. In high number of cycles fatigue better test; if some fatigue but not much, making some semicircular cope in the lesser members where meeting the chord should help.

 

[ishvaaag]

Just an alternative in

Recommended Practice for
Planning, Designing and
Constructing Fixed Offshore
Platforms—Working Stress Design
API RECOMMENDED PRACTICE 2A-WSD (RP 2A-WSD)
TWENTY-FIRST EDITION, DECEMBER 2000
ERRATA AND SUPPLEMENT 1, DECEMBER 2002
ERRATA AND SUPPLEMENT 2, SEPTEMBER 2005
ERRATA AND SUPPLEMENT 3, OCTOBER 2007

Thickening the chord ... maybe too much for just an architectural application.

It has guidelines for such design.