A finite element (FE) analysis of a CT25 specimen has been achieved for three configurations of a welded structure : monometallic (base metal), bimetallic (base metal and weld metal) and trimetallic (BM+WM+HAZ). Using the RICE-TRACEY model, a void growth parameter R/R0 has been computed for each case. The evolution of this parameter indicates clearly that the bimetallic specimen is the most harmful while the monometallic case leads to conservative results. Furthermore, a crack propagation analysis, based upon a critical value of the void growth rate, has been performed. Numerical and experimental tearing rates dJ/da are in good agreement but numerical J values are clearly underestimated. Concerning the trimetallic specimen, when analysing the void growth rate distribution around the crack tip, a prediction of crack propagation direction may be possible.
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