Calculations of Welded Joints

[NewMechanicalEngr]

If I am doing a simple load calculation on a steel member that was made of two pieces welded together, do I consider the member as a single piece or do I have to give special consideration to the weld?

Does the weld weaken the member and prevent me from looking at the member as a single piece?

If we do reduce the strength of the member, is there a factor to use? For instance, is the member 90% as strong now that it has a weld seam?

 

[Dinosaur]

These are questions you should discuss with your supervisor. As in most structural systems, it is often a chain controlled by the weakest link. Welding can provide the full strength of the member such as in complete joint penetration groove welds, or they can be substantially weaker than the member as you may see in stitch welds. Good Luck.

 

[HappyViking]

If the weld procedure qualification records for the weld can demonstrate an overmatching weld metal, and the weld has been inspected to demonstrate that there are no flaws (which would reduce the load bearing capacity of the weld), then in a strength design calc, the weld will not weaken the joint. BUT, you should also consider whether the fracture resistance of the member has been compromised by the intrinsic presence of flaws in the beam, and/or lower toughness microstructures in the welded joint.

 

[desertfox]

Hi

Have a look at these sites:-

http://www.utm.edu/departments/engin/lemaster/Machine Design/Lecture 33.pdf

http://www.utm.edu/departments/engin/lemaster/Machine Design/Lecture 34.pdf

regards

desertfox

 

[40818]

Welding introduces a "heat affected zone" which alters the local structural properties around the weld.