PSI - Issue 13

Primož Štefane et al. / Procedia Structural Integrity 13 (2018) 1895 – 1900 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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Results of FEA show good agreement with recorded P-CMOD history during fracture testing (Fig. 4.a) and with the evolution of J-integral versus load P normalized to limit load P Y (Fig. 4.b). Limit load P Y was defined from FEA and analysis of recorded strain field history using 3D DIC system. The analysis showed that plain strain field is prevailing in OM-UM SE(B) specimens while plain stress field is prevailing in UM-OM SE(B) specimens. Plotting the J-integral values normalized by stress biaxiality coefficient β against the distance between sharp fatigue crack front and UM-OM interface L 0 (Fig. 5.b) reveals an increasing trend as L 0 approaches 0. This might imply that J integral, normalized by β might be dependent solely on L 0 , thus providing an additional parameter for fracture toughness evaluation of heterogeneous materials and welds. However further parametric FEA study is necessary in order to confirm this hypothesis.

a

b

Figure 5 a) Finite element mesh and b) J-integral values normalized by β versus distance of crack tip from UM-OM interface obtained from FEA.

Acknowledgments

The authors would like to acknowledge ARRS (Slovenian Research Agency) and FWO Vlaanderen (Research Foundation — Flanders, research grant nr. G.0609.15N) for the support provided during this research.

References

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