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Hynek Lauschmann et al. / Procedia Structural Integrity 23 (2019) 107–112 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Coefficients of correlation of experimental and fractographic crack growth rates y = log(v) are (training/testing): specimen A1: 0.972/0.974; specimen A2: 0.968/0.927; specimen A3: 0.985/0.972. 5. Summary Fractographic reconstitution of the history of fatigue crack growth requires credible estimates of the course of crack growth rate. Within microfractography, it is being done on the basis of the striation spacing, e.g. Nedbal et al. (2008), Goldsmith et al. (2019). However, within this paper, tens of mesoscopic shape parameters (roughly speaking, describing shapes with dimensions at least in micrometres) have been found to solve this task as well. In comparison to striations, greater dimensions of shapes analysed do the method hopeful also in cases when the microrelief of fracture surface has been damaged. The newly applied method of statistical classification is an indispensable part of this methodology. Decomposition of the morphology of fracture surfaces into a set of dimensional components opens possibilities to study their relations to various sources: material microstructure, internal stresses, characteristics of fracture mechanics – e.g. the size of plastic zone, etc. Acknowledgement This work is part of project Centre of Advanced Applied Sciences with the number: CZ.02.1.01/ 0.0/0.0/16 019/0000778. Project Centre of Advanced Applied Sciences is co-financed by European Union. This work was supported by Czech Science Foundation (19-14237S). Banerji, K., 1988. Quantitative fractography: A modern perspective, Metallurgical Transactions A 19, Iss. 4, 961-971. Bastidas-Rodriguez, M.X., Prieto-Ortiz, F.A., Espejo, E., 2016. Fractographic classification in metallic materials by using computer vision. Engineering Failure Analysis 59, 237-252. Chermant, J.L., Coster M., 1979. Quantitative fractography. Journal of Materials Science 14, Iss. 3, 509-534. Goldsmith, N.T., Wanhill, R.J.H., Molent, L., 2019. Quantitative fractography of fatigue and an illustrative case study. Engineering Failure Analysis 96, 426-435. Jirou šková, K., 2018. The multilevel description of the morphology of fracture surface by characteristics of roughness and morphometry (Research project, in Czech). Kapłonek , W., Nadolny, K., Królczyk , G.M., 2016. The Use of Focus-Variation Microscopy for the Assessment of Active Surfaces of a New Generation of Coated Abrasive Tools. Measurement Science Review 16, Iss. 2, 42-53. Khokhlov, M., Fischer, A., Rittel, D., 2012. Multi-Scale Stereo-Photogrammetry System for Fractographic Analysis Using Scanning Electron Microscopy. Experimental Mechanics 52, Iss. 8, 975-991. Lauschmann, H., Goldsmith, N., 2009. Textural Fractography of Fatigue Fractures, in: Fatigue Crack Growth: Mechanics, Behavior and Prediction . Alphonse F. Lignelli (Ed.). Nova Science Publishers, 125-166. Merson, E., Danilov, V., Merson, D., Vinogradov, A., 2017. Confocal laser scanning microscopy: The technique for quantitative fractographic analysis. Engineering Fracture Mechanics 183, 147-158. Merson, E.D., Danilov, V.A., Linderov, M.L., Myagkikh, P.N., Merson, D.L., Vinogradov, A., 2018. Assessing Fracture Surface Ductility by Confocal Laser Scanning Microscopy. Procedia Structural Integrity 13, 2152-2157. Nedbal, I., Siegl, J., Kunz, J., Lauschmann, H., 2008. Fractographic reconstitution of fatigue crack history - Part I. Fatigue & Fracture of Engineering Materials & Structures 31, 164-176. Nedbal, I., Lauschmann, H., Siegl, J., Kunz, J., 2008. Fractographic reconstitution of fatigue crack history - Part II. Fatigue & Fracture of Engineering Materials & Structures 31, 177-183. Sahu, S., Yadav, P.C., Shekhar, S., 2016. Fractal Analysis as Applied to Fractography in Ferritic Stainless Steel. Metallography, Microstructure, and Analysis 6, 598-609. Schlesinger, M.I., Hlaváč, V. , 2002. Ten Lectures on Statistical and Structural Pattern Recognition. Springer Science & Business Media. Spear, A.D. , Shiu, F.L., Lind, J.F., Suter, R.M., Ingraffea, A.R., 2014. Three-dimensional characterization of microstructurally small fatigue-crack evolution using quantitative fractography combined with post-mortem X-ray tomography and high-energy X-ray diffraction microscopy. Acta Materialia 76, 413-424. Xu, M., Xu, J., Lu, H., Chen, J. , Wei, X., 2015. Fractal and probability analysis of creep crack growth behaviorin 2.25Cr – 1.6W steel incorporating residual stresses. Applied Surface Science 359, 73-81. References