Stl63
Structural
- Jul 27, 2007
- 31
When stiffening a duct plate with single angles, you create a cross section of an unsymmetrical built-up shape; using an effective plate width of 16xt. The tip of the toe of one leg is welded to the plate.
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AISC 360-10 provides for flexure in unsymmetrical shapes in chapter F12. This provides a Yielding limit of Mn=Fy Smin. However, it does not supply guidance on Fcr for LTB and LB. When the outstanding angle leg is in compression for this unsymmetrical shape.
1) Why does this not allow for Mn=Fy Z?
2) What would be a method to determine LTB limits?
3) If the leg (flange) is non-compact, what would be an allowable local buckling limit?
''''''''''!
____!____
AISC 360-10 provides for flexure in unsymmetrical shapes in chapter F12. This provides a Yielding limit of Mn=Fy Smin. However, it does not supply guidance on Fcr for LTB and LB. When the outstanding angle leg is in compression for this unsymmetrical shape.
1) Why does this not allow for Mn=Fy Z?
2) What would be a method to determine LTB limits?
3) If the leg (flange) is non-compact, what would be an allowable local buckling limit?
