Bend testing shear stud
The test (bend testing shear stud) serves as a simple bench test for approximate checking of the chosen welding data. In the test, the weld is subjected to bending in an undefined manner. If arc blow or another visible imperfection is suspected, the stud shall be bent in a manner such that the area to be examined is in the tension zone. This can be done by one of the two following methods.
- The studs are bent through 60° using drawn arc stud welding with ceramic ferrule or shielding gas, or short-cycle drawn arc stud welding, through 30° using capacitor discharge stud welding with tip ignition or capacitor discharge drawn arc stud welding(see the following figure)
- The studs are stressed by applying a bending moment below the elastic limit
Note: Values of bending moments for studs by applications > 100 °C are given in the following Table
Bending moments based on stud diameter
|Stud diameter(d)mm||Bending moment(Nm)|
Bend testing shear stud is a much informative qualitative procedure simple to perform.
When applied to welded specimens, it evaluates both the ductility and soundness of welds, without instrumented equipment.
Weld bend testing ensures the heat affected zone, as well as the weld itself, did not become brittle during the weld process. Testing may include face bend, root bend or side bend testing as specified. Usually two bend tests are performed on each face, root or side.
The specimens for bend testing are cut from a single weld plate submitted for testing. Test specimens may range in size from 6×6 inches to 8×24 inches, according to customer drawings or specifications.
The specimen is bent around a mandrel with a specific radius according to the applicable specification. The specimen is visually inspected for cracks, orange pealing or discontinuities in the bent surface. Each defect is noted on the report.