PSI - Issue 35

M. Faruk Yaren et al. / Procedia Structural Integrity 35 (2022) 98–105 Yaren M. F. et al / Structural Integrity Procedia 00 (2021) 000 – 000

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Fig. 2. Effect of block overload size on crack growth life.

As seen in Fig. 2, the effect on crack growth life is inversely proportional to the size of the overload cycle. It can be deduced that; although the number of cycles is low, overloads are applied more frequently and each time new expanded plastic zones, through which the crack tip must pass slowly and repeatedly, are created. The same effect can be seen in test data under plane-stress condition by Porter (1972).

Fig. 3. Comparison of calculated lives using different models for block overloading, n = 10, 50, 200, 500.