Strenght of Full Penetration Bevel weld

[OffshoresMech]

Hello,

Working on the lifting lug/padeye design. The lug is basically a steel plate 32mm thick by 500mm long by 330mm high (with an opening for attachment), and it is attached to the I-beam of the frame by a welded joint. The padeye is obviously in tension as the structure is being lifted but there is also a perpendicular component (5% of the upward force), so there is going to be stress from bending in addition to the tension in the welded joint.

My queston is, if the padeye is attched to the beam by a full penetration butt weld along the 500mm edge on both sides, can you assume the weld area to be equal to base material area, and thus don't bother calculating stresses in the weld but only the stresses in the x-section of the plate (500mm x 32mm)?

Quick search on the internet (and some thinking) points into that direction, however I also found some oposing views. And so I'am a little confused.

This is my first post, so please be patient.

Thank you.

 

[metengr]

OffshoresMech;
Are you using AWS D1.1 as the construction code for this application? Regarding a full penetration weld, if this is indeed the case, the cross-sectional area of the weld would be near equal with the surrounding base metal.

The concern is what design margin to use for the weld metal itself because this is considered as an as-cast structure and could contain minor defects. To account for this, other codes of construction that require full penetration welds may assign a strength reduction factor for the weld – like 0.85 on top of a design margin for use in service. You need to investigate this before proceeding.

 

[OffshoresMech]

metengr,

thank's a lot for the remarks. I appreciate it.

oh, and yes AWS D1.1.

 

[ash060]

Full pen welds are controlled by the base material only as per Table J2.5 (unless the filler material is not as strong as the base metal) of the AISC code.