PSI - Issue 13

Wei Song et al. / Procedia Structural Integrity 13 (2018) 2227–2232

2230

4 Author name / Structural Integrity Procedia 00 (2018) 000 – 000 toe, either the undermatched (UM) welded joints or the evenmatched (EM) welded joints. With the deceases of penetration length, the failure location transites to weld root. In terms of 0.5 P ratio, joints failure locations occurs at weld root for UM welded joints, while the failure locations of EM welded joints occurs at weld toe. It means that it is uncertained for the medium penetration length due to the combined effects between geometry and mismatch. For the fully incompleted penetration (Penetration ratio=0) ， the fatigue failure locations for UM and EM welded joints are located in weld root. It should be noted that weld toe crack initiation of UM welded joints tends to propagate along with HAZ.

Fig. 3. Monotonic stress-strain curves of 10CrNi3Mov high strength steel and corresponding welds.

Fig. 4. The comparison between monotonic stress strain curves and cyclic R-O relationship curves at the middle of fatigue life for base metal and undermatched weldments.

Fig. 5. Weld toe and weld root failure of LCWJ under different penetration ratio and material mismatch.