AISC


8.2. Groove Welds

8.2.1. Are weld quality criteria applicable to the root area of partial-joint-penetration groove welds?

No. Attempts are sometimes made to apply weld quality criteria to the root area of partial-joint-penetration groove welds. Evaluation of weld quality in the root area should be limited to the verification of proper joint penetration, as provided in AWS D1.1:2004 Section 2.3.1, and proper welding procedures.

last modified 22 April 2004

8.2.2. When a weld is placed between plates forming an angle that is less than 60 degrees, why is a Z loss factor applied to determine the effective throat?

The Z loss factor is applied at angles below 60 degrees to recognize that this weld cannot reliably penetrate to the root of the joint and is thus a partial-joint-penetration groove weld; see Figure 8.2.2-1. Note that, below 30 degrees, this joint is no longer prequalified.

last modified 13 September 2002

8.2.3. What is the difference between a flare weld and a partial-joint-penetration groove weld?

A flare weld is a special kind of partial-joint-penetration groove weld wherein the convex surface of the connected part(s) creates the joint preparation.

last modified 13 September 2002

8.2.4. What purpose does a weld access hole serve?

The primary purpose of a weld access hole, as the name implies, is to allow the welder access to start and stop the weld beyond the plane of a beam web or other obstruction. At the same time, the weld access hole also minimizes restraint to allow for shrinkage in the welded joint and eliminates the intersection of welds in orthogonal directions (and the associated intersection of stresses).

last modified 13 September 2002

8.2.5. When should backing bars and run-off tabs be removed after welding?

To produce sound welds on many welded joint geometries, run-off tabs projecting from the finished member may be required to permit starting and stopping welds beyond the edge of the member; AWS D1.1:2004 Sections 5.10 and 5.31 should be followed. When such welding aids are required to be removed, the surface should be finished as indicated in 2.2.6 and 2.2.7.

Damage to welded beam-to-column-flange moment connections in the 1994 Northridge earthquake has raised several welding and seismic detailing issues and new criteria have been established. Explicit requirements for the removal of back-up bars and run-off tabs in seismic projects are included in the 2005 AISC Seismic Provisions and corresponding Supplement No. 1. An exception is included for tested assemblies that can be demonstrated to have acceptable performance with alternative treatments.

last modified 1 January 2006