Weld for Wide Flange shape with Cover Plate
Weld for Wide Flange shape with Cover Plate
(OP)
When adding a cover plate to a wide flange section flange, to increase section modulus and moment of inertia, is it necessary to provide a continuous weld vs. a weld with spaces.
If the plate is A36 steel and the WF is A992, how is the new section modulus figured.
If the plate is A36 steel and the WF is A992, how is the new section modulus figured.






RE: Weld for Wide Flange shape with Cover Plate
The stitch weld would preferrably be at least a 1 1/2" [38 mm] long weld each side and spaced perhaps between 6 and 12 inches [150 to 300 mm] on center - maybe closer depending on strength.
AISC has a nice section at the end of Chapter B that outlines special requirements for the end of the cover plate where you need a length of solid weld beyond the point where the cover plate is no longer required.
Section modulus does not depend on Fy - at least as long as you are in the elastic range of stress.
RE: Weld for Wide Flange shape with Cover Plate
The new section moment of inertia is calculated using composite section Parallel-Axis Theorem.
RE: Weld for Wide Flange shape with Cover Plate
I may add that the section modulus does not depend on Fy, however you will need to check stesses in the plate as well as in the wide flange section, and compare them to the allowable stresses.
The allowable stresses in the plate and the wide flange section will be different based on Fy.
Good luck.
RE: Weld for Wide Flange shape with Cover Plate