Strehgthening of Existing Steel Column
Strehgthening of Existing Steel Column
(OP)
When enhancing the capacity of the existing wide flange steel columns by welding plates flush with the flanges of the column, do I need to consider any reduction in KL/R of the stiffened section for calulation of Fcr?? I am not sure as to whether the modified KL/R equation for built-up members is applicable in this case. Any guidance in this regard is greatly appreciated. Thank you.






RE: Strehgthening of Existing Steel Column
Yes
RE: Strehgthening of Existing Steel Column
Thanks for the clarification. Now, for the evaluation of separation ratio to be used in the calculation of modified KL/R, what does the term "h" mean. Is it the distance between the centroids of the plates being welded??
RE: Strehgthening of Existing Steel Column
Depending on the size of added plate, Ry could increase or decrease. If it decreases, KL/R increases and you need to consider it.
Perhaps it is best to provide a sketch showing what you intend to do.
BA
RE: Strehgthening of Existing Steel Column
RE: Strehgthening of Existing Steel Column
RE: Strehgthening of Existing Steel Column
RE: Strehgthening of Existing Steel Column
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Strehgthening of Existing Steel Column
is this applicable also regardless of the failure axial or moment?
the way i understand it if it's axial failure it should be continues weld to have continues increase in area
RE: Strehgthening of Existing Steel Column
delagina-
That's where the modified KL/R comes into picture. The KL/R calulated based on the assumption that the whole section acts as a single unit is modified for welds not being continuous. This is addressed in the "Compression of built-up sections" part of the AISC manual. That is where I am stuck now....having hard time interpreting the term "alpha" in the equation E6-2. The AISC manual calls it separation ratio.
RE: Strehgthening of Existing Steel Column
BA