Welding 2 H beams together end to end with Z weld

By 2_rule Date 04-27-2011 13:51

Hi everyone.
I am looking for some help about this kind of beam connection. I draw a simple sketch to make it clear as you can see . We are now working with Saudi Arabs(this is the reason of problem) and they have doubt about this kind of connection. Even we suggested to make an weld strength calcualtion , all they want is see this kind of connection is proper for connecting Beams in a welding or manufacturing code. I know most of you have made this connection for years but i am asking is there anyone has any code or standard that shows this connection type .

http://www.resimpaylas.org/data/media/29/Yeni_Resim.jpg

Thank you all

By jwright650 (*****)

Date 04-27-2011 14:19

I've seen this question posed to the forum several times over the years and don't think much of it...seems very expensive and gains nothing.

Seems like alot of work when I regular AWS D1.1 full pen splice should work...provided the beam was sized correctly for the application to start with. You can't develope anymore strength than what the beam will carry to start with anyway and a properly executed full pen splice is supposed to develope that much. By zig-zagging the cut...you just added more work to properly bevel and weld it together. A straight cut would be better/more cost effective in my opinion.

B-U4b for the flanges and web.

By qcrobert (***)

Date 04-27-2011 14:32

I concur with jwright in that the zig-zag connection is not stronger than a regular straight cut CJP weld connection.

In fact the zig-zag connection may create problems with start/stop junctures (cold starts, slag inclusions, ect).

QCRobert

By 803056

Date 04-29-2011 05:12

There is no need to use the "Z" configuration when working with carbon steels or HSLA steels. The allowable stresses for the CJP welds are the same as the allowables for the base metal.

As mentioned by QCR, the welds intersecting at right angles can produce residual stresses that can result in a potential for forming cracks at the weld intersects. The problem is more pronounced with the higher strength steels than it is for the lower strength steels. The residual stresses that are on the same order of magnitude as the yield strength of the base metal. The stresses can be added as vectors. If the resultant is greater than the tensile strength, there is a potential for crack formation.

Two intersecting welds in ASTM A36 will be successful, but two intersecting welds in ASTM A992 will be very prone to crack formation at the intersect. The higher strength steels have reduced ductility compared to the lower strength steels, so the lower strength steels can accommodate high stresses by plastic deformation. HSLA steels typically have higher stress and reduced ductility capable of accommodating the high residual stresses.

Best regards - Al