Experimental Study forthe Effect of Additional Weld on Fatigue Strength inOut-of-Plane Gusset Welded Joints

Abstract

Grinding of weld toes is generally used to improve the fatigue strength of fillet weld joints. In this study, a technique employing additional welds was applied to out-of-plane gusset welded joints and the relationship between the shape of the additional weld and fatigue strength was investigated. The shape of the additional weld was controlled by changing the aiming position. When there was more distance between the first weld toe and the aiming position of the additional weld, the flank angle and toe radius tended to be smaller and larger, respectively. In the nominal stress range of 150 MPa, fatigue life was extended to 2.7 times that of weld joints without additional welds. Although the toe radius of the additional weld was smaller than that created by grinding, the resultant fatigue strength of the additional weld joint was almost equivalent to that of the grinding case. This can be explained in terms of stress concentration, since the flank angle and toe radius in the additional weld toe can be improved without reducing the throat thickness.

Effects of additional weld and grinding on fatigue life extension of non-load-carrying cruciform joints

“…The fatigue performance of the joints was evaluated numerically based on the prediction of fatigue crack initiation and propagation lives, where the bead geometry, angular distortion and changes in material properties by weld heat were considered [9][10][11][12][13][14] . The FE 1.…”

“…Fatigue failure of weld structures is often initiated around the welded parts due to a series of factors, such as stress concentration caused by the geometry of the welding bead, changes in material properties by heat input, residual stresses and deformations. On the other hand, grinding, TIG treatment, peening, etc., are available to improve the fatigue strength of welded joints [1][2][3][4][5][6][7][8][9][10][11][12][13][14] . Some of those methods have been standardized in JSSC 3) as improving methods to enhance the fatigue performance of joints.…”

“…Some of those methods have been standardized in JSSC 3) as improving methods to enhance the fatigue performance of joints. The application of additional welding is also one of the techniques adopted for reducing the stress concentration at the weld toe, and it is relatively easy to actuate 8,10,[12][13][14] .…”