Electromagnetic signature of prefracture criticality in heterogeneous media.
Fractal statistical analysis under the critical point (CP) hypothesis is applied to electromagnetic (EM) signals emitted before failure. A new approach to the analysis of a possible EM fractal pattern evolution toward CP is suggested. The analysis reveals characteristic signs of approaching the CP: the emergence of memory effects; the increase of the spatial correlation; the decrease of the antipersistence behavior; the appearance of persistence properties in the tail of the precursors, a loss of multifractality, and, finally, the divergence of the energy release rate. These critical features are compatible with the percolation theory of fracture process.
Solid State Section, Physics Department, University of Athens, Athens, Greece. pkapiris@cc.uoa.gr
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Kapiris
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Eftaxias
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Chelidze