PSI - Issue 59

M. Karuskevich et al. / Procedia Structural Integrity 59 (2024) 642–649 M. Karuskevich et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 5. Uniaxial Fatigue Indicator of different sensitivity.

As proved by the Finite Elements Analysis, the geometry of the indicators influences local stresses in the mid sections of the indicators (Fig. 5). Thus, the possibility of the indicator’s sensitivity variation exists. 4. Cruciform biaxial fatigue indicator Success in developing the uniaxial fatigue indicator has naturally come to the attempt to use the same principle for fatigue monitoring at biaxial loading. In the process of the search for the optimum geometry for the biaxial indicator, its shape evolved from the shape of the typical cruciform specimen to the design providing the required sensitivity and possibility to monitor the indicator’s state in the selected spot in the correct way. The design of the cruciform specimens is well described in many papers devoted to the biaxial tests (Mitukiewicz et al., 2021 and Lu, 2020). The proposed biaxial indicator relies on some decisions taken from samples for biaxial loading and was developed by iterative improvement procedure (Fig. 6).

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