PSI - Issue 28

M.R. Tyutin et al. / Procedia Structural Integrity 28 (2020) 2148–2156 TyutinM.R./ Structural Integrity Procedia 00 (2020) 000–000

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Fig.5. Dependencies of the relative area of the damaged surface S * on the relative deformation ε* (a); dependencies of the coercive force H C on the relative area of the damaged surface S * (b) for the steels studied. 4. Conclusions A relation between the damage characteristics of structural steels, their physical properties, including acoustic and magnetic parameters was found. It was shown that:  The sensitivity of non-destructive testing methods and damage accumulation rate significantly depends on the fracture stage and the material structure  Analysis of changes in the estimated physical characteristics and acoustic emission parameters made it possible to distinguish four stages of fracture.  The stages of damage accumulation correspond to the fracture stages identified analyzing the changes in acoustic emission parameters and in magnetic characteristics.  Interrelations between the coercive force values H C with real damage parameter S *, not previously noted in the literature, were established. Acknowledgements The study was supported by the Russian Science Foundation (project №19-19-00674). References [1] J. Lemaitre, A Continuous Damage Mechanics Model for Ductile Fracture, J. Eng. Mater. Technol. 107 (1985) 83–89. doi:10.1115/1.3225775. [2] P.-O. Bouchard, L. Bourgeon, S. Fayolle, K. Mocellin, An enhanced Lemaitre model formulation for materials processing damage computation, Int. J. Mater. Form. 4 (2011) 299–315. doi:10.1007/s12289-010-0996-5. [3] V. Tvergaard, A. Needleman, Analysis of the cup-cone fracture in a round tensile bar, Acta Metall. 32 (1984) 157–169. doi:10.1016/0001-6160(84)90213-X. [4] L.R. Botvina, T.B. Petersen, A.P. Soldatenkov, M.R. Tyutin, Time dependences of acoustic signal characteristics during fracture of metal samples, Dokl. Earth Sci. 462 (2015) 475–478. doi:10.1134/S1028334X15050037. [5] A. Carpinteri, G. Lacidogna, S. Puzzi, Chaos, Solitons and Fractals From criticality to final collapse: Evolution of the ‘‘b-value” from 1.5 to 1.0, Chaos, Solitons and Fractals. 41 (2009) 843–853. doi:10.1016/j.chaos.2008.04.010. [6] A. Carpinteri, G. Lacidogna, N. Pugno, Structural damage diagnosis and life-time assessment by acoustic emission monitoring, Eng. Fract. Mech. 74 (2007) 273–289. doi:10.1016/j.engfracmech.2006.01.036. [7] P. Datt, J.C. Kapil, A. Kumar, Acoustic emission characteristics and b-value estimate in relation to waveform analysis for damage response of snow, Cold Reg. Sci. Technol. 119 (2015) 170–182. doi:10.1016/j.coldregions.2015.08.005. [8] W.H. Prosser, M.R. Gorman, D.H. Humes, Acoustic emission signals in thin plates produced by impact damage, J. Acoust. Emiss. 17 (1999) 29–36. http://ntrs.nasa.gov/search.jsp?R=20040086468 (accessed September 28, 2016).