PSI - Issue 64

Arij Fawaz et al. / Procedia Structural Integrity 64 (2024) 89–96 Arij FAWAZ/ Structural Integrity Procedia 00 (2019) 000 – 000

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in certain cases where the FPZ is sufficiently large. Moreover, the strain curves obtained from optical fiber showed that for few cases, the FPZ occupies a significant portion of the crack propagation region in the adhesive. Thus, determining the position of the crack tip within a plateau of maximum strain values can be challenging. In these cases, the uncertainty in crack length might affect the G IIC values and lead to dispersion in G IIC values. 5. Conclusion This study demonstrated the effectiveness of employing optical fiber in an ELS test. Optical fiber enables the real time monitoring of crack propagation and provides accurate crack length measurements at each time increment during the test. In this research, a new sample configuration is proposed allowing for the combination of two setups: ELS and 4-points bending creep tests. Results from both configurations were compared. The G IIC values calculated using two data reduction methods. A dispersion of G IIC values is obtained for these methods for both configurations. This dispersion mainly arises from the assumptions that are considered in the used formulas in the two data reduction methods. Thus, some formulas outlined in the ISO 15114:2014 standard need modification to be applicable to the geometry of both configurations. With the aim of validating the new proposed configuration, additional investigations are needed to develop it. Digital image correlation will be used later to compare the J-integral for both configurations. Once the proposed methodology is validated, samples will be aged under constant load (creep) and then tested using ELS test with configuration 2 as the geometry for all samples. This thorough study should bring interesting information by presenting load influence on the mechanical properties of adhesively bonded reinforcements or repairs. 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