When designing a weld, several factors must be taken into consideration, such as the weldability of the base metal, the match between the welding materials and the base metal, the welding efficiency, the welding method, the size of the weld bead, the welding deformation and buckling. of the joint plate.
Related Reading: The Ultimate Guide to Welding
Let's consider fillet welds as an example.
According to the American Welding Society's Steel Structure Welding Code (AWSD1.1), fillet weld beads are classified into three categories, which are ideal weld bead, acceptable weld bead width and weld bead unacceptable.
Inadequate fillet weld throat depth, excessive convex surface, weld corrosion, overlap, insufficient leg length, and poor fusion are considered incorrect weld bead dimensions.
The minimum fillet weld bead size is also specified in the Steel Structure Welding Regulations of the American Welding Association and the China Technical Code for Steel Structure Design of Steel Buildings. Table 4 illustrates the minimum fillet weld size. fillet weld bead.
The minimum leg length of fillet welding is determined by the thicker plate of the two parts of the joint, but should not be greater than the thickness of the thinner plate.
If the minimum leg length is exceeded, sufficient preheating must be provided to ensure welding quality.
Related Reading: Welding Quality of Welded Joints
If stress calculations require it, the weld size may exceed the thickness of the thin plate at the joint.
Table 3 lists the minimum fillet welding leg length for different sheet thicknesses, while Table 4 demonstrates the correlation between the total fillet welding pass width and the maximum convex face length.
Table 3 Minimum Fillet Weld Bead Angle Length
| Thickness of the thickest plate at the joint, t (mm) | Minimum fillet weld leg length (mm) |
| t≤6 | 3 |
| 6＜t≤12 | 5 |
| 12＜t≤19 | 6 |
| 19＜t≤38 | 8 |
Table 4 Relationship between total pass width and maximum convex fillet welding length
| Total width of the weld bead, w | Maximum length of the convex face, c |
| w≤8mm | 1.6mm |
| 8mm＜w≤25mm | 3mm |
| 25mm＜l | 5mm |
