PSI - Issue 17

Michal Vyhlídal et al. / Procedia Structural Integrity 17 (2019) 690–697 Vyhlídal et al./ Structural Integrity Procedia 00 (2019) 000 – 000

697

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6. Conclusion

Stability criterion based on the average value of tangential stress ahead of the crack tip seems to be suitable for determination of the maximum load, while the value of crack mouth opening displacement is, due to tensile softening, underestimated. However, the most important variable for the design of structures is still the maximum load thus from that point of view is this criterion sufficient. From the detailed numerical analysis of the described fracture test, we concluded that the actual crack length 0 must be greater than it was supposed. In other words, diamond blade saw damaged the specimen more than expected. This damage is due to the small distance between the bottom corner of the cavity and the crack tip, which is approximately 2.34 mm. It is obvious that such a small area above the crack tip cannot resist the load that is caused by cutting the specimen by diamond blade saw and must inevitably lead to its partial failure. Real crack length a 0 is approximately 13.5 mm (for specimens 1 and 2) and 13 mm (for specimen 3).

Acknowledgements

This outcome has been achieved with the financial support of the Brno University of Technology under project No. FAST-J-19-6079.

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