PSI - Issue 47

Irina A. Bannikova et al. / Procedia Structural Integrity 47 (2023) 602–607 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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The deformation and fracture can be represented as a sequential combination of two processes: the first is the impact type fracture that is realized when one or two main cracks are formed, and followed by complete fragmentation of the sample. We assume that this is due to the presence of two different mechanisms of fragment formation during fracture. Statistical distributions of fragments in the range of small scales (masses of fragments), close to the "power law" type distributions, reflect self-similar fracture when the energy density limit in the sample volume is reached over a wide range of scales. Large fragments comparable to the characteristic size of cylindrical specimens were formed as a result of the passage of main cracks and were described mainly by an exponential or logarithmic function, which corresponds to the model of N. Mott in the failure of metal shells (Grady (2006)). The analysis of fracture surface of 2D fragments (ceramics) by interferometer profilometer New View and optical microscope HIROX KH 7700 showed that the formation of small fragments depends both on the initial porosity of the sample and on the loading, energy providing the formation of 2D fragments. 4. Conclusion Data on statistical distributions of fragments allow the understanding of mechanisms of failure of brittle and quasi brittle materials (ceramics, natural materials) in a wide range of load intensities. The qualitative difference of these mechanisms is illustrated by the change of type of statistical distributions: transition from a combined exponential power laws to a power law, or the combination of mentioned laws. All these types of distributions show the qualitative different mechanisms of damage-failure transitions corresponding to the nature of materials and load intensity and can be considered as the effective experimental tool to estimate the energy absorption properties of these materials in wide range of load intensity. Acknowledgements This research was supported by the Russian Science Foundation (project 21-79-30041), https://rscf.ru/en/project/21-79-30041/. References Astrom, J., Linna, R., Timonen, J., 2004. Exponential and power-law mass distributions in brittle fragmentation. Phys. Rev. E. 70, 026104. Bannikova, I., Uvarov, S., Naimark, O., 2014. Analysis of fragmentation statistics of alumina tubular specimens. AIP Conference Proceedings 1623, 59-62. Bannikova, I., Naimark, O., Uvarov, S., 2016. Transition from multi-center fracture to fragmentation statistics under intensive loading. Procedia Structural Integrity 2, 1944-1950. Bannikova, I., Uvarov, S., 2021a. Experimental study of fragmentation of fused quartz cylinders under quasi-static loading with the fractoluminescence recording. Procedia Structural Integrity. 32, 10–16. Bannikova, I., Uvarov, S., 2021b. Scaling laws in fragmentation dynamics of rock materials. Procedia Structural Integrity. 33, 357–364. Davydova, M., Uvarov, S., 2013. Fractal statistics of brittle fragmentation. Fracture and Structure Integrity 24, 60-68. Davydova, M., Uvarov, S., Naimark, O., 2014. Scale Invariance in Dynamic Fragmentation of Quartz. Physical Mesomechanics 17(1), 81-88. Davydova, M., Uvarov, S., Naimark, O., 2016. Space-time scale invariance under dynamic fragmentation of quasi-brittle materials // Physical Mesomechanics 19(1), 86-92. Grady, D., 2006. Fragmentation of rings and shells. In: Springer,Verlag Berlin Heidelberg, Printed in Germany, pp. 374. Kats, M., Simanovich, I., 1974. Quartz of crystalline rocks (Mineralogical features and density properties). Proceedings 259. In: Nauka Publisher, Moscow. (In Russian). Katsuragi, H., Sugino, D., Honjo, H., 2003. Scaling if impact fragmentation near the critical point. Phys. Rev. E. 68(4), 046105. Katsuragi, H., Sugino, D., Honjo, H., 2004. Crossover of weighted mean fragment mass scaling in two-dimensional brittle fragmentation. Phys. Rev. E. 70(62) P. 065103. Naimark, O., 2016. Some regularities of scaling in plasticity, fracture, and turbulence. Physical Mesomechanics 19(3), 307-318. Naimark, O., Uvarov, S., Davydova, M., Bannikova, I., 2017. Multiscale statistical laws of dynamic fragmentation. Physical Mesomechanics 20(1), 90-101.