Strength verification of circular crown arch-shaped fillet welds under static loads

Due to the lack of literature studies on the use of analytical methods to determine the stress distribution in curved fillet welds, this study proposes an analytical procedure to determine the stresses in curved fillet welds subjected to an eccentric force coplanar with one of the fillet sides. The procedure is based on the theory of infinitely rigid bodies and the principle of superposition of effects, valid for steel in the elastic range. The procedure is then used to determine the strength of a fillet weld with circular crown arch shape, under different inclination and locations of the external force. Two scenarios are examined: one accounting for the eccentricity of the applied force relative to the centroid of the flipped throat surface, and one without it. Based on the results, the most unfavorable directions of the external force are identified. These findings are then used to determine the optimal location of fillet welds with circular or elliptical crown arch shapes, considering variations in force inclination, force location, and fillet configuration. It is also found that, when the force is applied at the centroid of the flipped throat surface, the magnitude of force resisted by the fillet is independent of its inclination only if the fillet is subtended by a central angle greater than or equal to 180°. Conversely, the fillet cross-section(s) experiencing the most critical stress state is(are) the end section(s) of the fillet. Moreover, a comparison with an established method demonstrates that the proposed approach yields accurate and reliable results. The findings of this study provide valuable insights into the design and strength verification of curved welded joints, aiding engineers in optimizing their design.