PSI - Issue 13

Yanzeng Wu et al. / Procedia Structural Integrity 13 (2018) 890–895 Yanzeng Wu et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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elastic parameter, is the same for them. This phenomenon is related to the influence of its distinguishing microstructure, there is a lower plastic defamation for HAB by comparing the value of CTOD corresponding to the maximum applied load from Fig. 6. Hence, this means that the fatigue crack growth rate is intimately linked to the plastic deformation of the crack tip, which is also consistent with analyses by Vasco-Olmo et al. (2017). According to the above results, the area of the CTOD loop may be used as a viable alternative in characterizing fatigue crack growth. The area of the CTOD is relevant to the crack opening load and the value of CTOD corresponding to the maximum applied load in the fatigue cycle.

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Fig. 5. Variation of relative displacement with load for HAB and non-HAB zones at the different location along the crack: (a) 10 pixel. (b) 50 pixel. (c) 100 pixel.

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Fig. 6. CTOD loops within a full loading cycle: (a) HAB zone in the layer band. (b) non-HAB zone between layer bands.