I am looking for a method for analyzing a flat head design with welded, radial stiffeners. UG-47 does not seem to apply. Thanks for any help.

Hello rcrowe

It is possible to do such an analysis, but very unwise.

The principle of a beam requires that the beam is continuous. If a beam is interrupted as would be the case with a radial arrangement, because where they meet in the centre is a welding problem, the bending moment is not transferred across the centre junction. I know a design can be proposed where there is a central ring up against which radiating arms abutt. This is not as easy as it sounds. The problem is that the ring is too flexible, and again, the moment is not transferred across the diameter of the ring. If a ring is used, it must be covered with a cover or cap plate to stiffen the ring against flexure. However the stress in the region of the ring are difficult to analys with confidence.

A better scheme is to use parallel beams to divide up the flat cover into panels, each of which can be analyzed in accordance with UG-37 or UG-47 of ASME Division 1.

This is easy to analyse.

Care must be taken to ensure the welding between the beam and the cover is adequate. If for example, during bending, the cover is tending to pull away from the beam, the weld can fail. There is also a shear stress in the weld too.