Location of seam for HSS

By zfq211314 Date 10-18-2019 08:40

Hello Everyone,
The raw material subcontractor informed us they will change location of welding seam from long side to short side for RHS,we need to evaluate the risk for change.
We create Escalator truss frame and require the welding seam of RHS,both for upper chords and bottom chords ,should face to inside of frame in current process,if we change the location of seam,which direction the short side of RHS with welding seam should face to? Is there any risk for this change?

BR
Frank.

Attachment: RHSFRAME.pdf (8k)

By Tyrone

Date 10-18-2019 11:31

Hey zfq,
Welcome to the Original AWS Welding Forum.

You have to know how the weld will be subjected to a load. Then it can be compared.
Take for example my mark-up of one load case. The before change seam weld will potentially see some compressive stress and possible buckling. The after change weld will see minimal stress since the non-welded legs of the tubing will take the load.

So...all depends on how it will be loaded.

Tyrone

By 803056

Date 10-18-2019 14:18

You didn't provide a side view of the "truss", but in a traditional truss, the top chord is loaded in compression, the bottom chord in tension. Where the seam is located shouldn't be an issue.

If the top chord has a uniform load applied, it would be subject to bending. Again, I don't believe the location of the seam should be an issue.

Al