CJP Welds and the k section

Date 07-14-2005 11:10

On columns with full pen welds on the flanges should you or should you not fill the kerf where the corner of the stiffener was cut to allow it to sit on the web? What are the possible problems that could occur if it should not be done but someone did it anyway? Better yet if you were a 3rd party inspector and you had to inspect it would you allow it?

By swnorris (****)

Date 07-15-2005 11:17

I have seen it both ways but I can t give any solid references to support either side. Past experiences have been that this area is subject to weld cracking. I had a welding inspector tell me he had never seen them not welded. Certain jobs we've done in the past have had specific instructions in their specs to terminate the welds a minimum and maximum distance back from the K dimension. Just beware of the cracking possibility that exists when these are welded within the K distance.

By thcqci

Date 07-15-2005 12:54

I would opt to not weld these clipped corners, but I have no real verbiage anywhere to back that up. In a related issue, filling rat holes of CJP welds in beams or columns ( http://www.aws.org/cgi-bin/mwf/topic_show.pl?id=3946#15995 ), it was decided that welding in this area was not advised. This situation is similar enough to make me lean that way. Best thing to do would be to get the engineer involved in the decision. Hopefully the engineer has welding related knowledge to help make that decision.

By swnorris (****)

Date 07-15-2005 16:06

I decided to pose the "to weld or not to weld" question to the AISC. Here is their response:
Welding should always be avoided at or near the k-area of the shape. The k-area may have reduced ductility due to cold straightening at the mill. Also, the k-area is the slowest to cool after the shape is hot rolled, so it will contain more of a course micro-structure. This combination can sometimes lead to brittle crack propagation within the k-area. The following paper discusses test findings:

http://aisc.org/template.cfm?template=/Ecommerce/ProductDisplay.cfm&ProductID=2170

By DGXL

Date 07-15-2005 17:46

The D1.8 (when published) will note leaving the weld out of the K area, as do the FEMA recommendations. Specific clip/stiffener/continuity plate details and dimensions for weld termination are noted within.