Issue 40

I. Stavrakas, Frattura ed Integrità Strutturale, 40 (2017) 32-40; DOI: 10.3221/IGF-ESIS.40.03 38 Figure 7 : The behaviour of the PSC, shown in logarithmic scale, with respect to the value of the mechanical stress. Figure 8 : The behaviour of the PSC cumulative energy, shown in logarithmic scale, with respect to the value of the mechanical stress. Fig. 8 shows the behaviour of the released cumulative energy of the PSC in logarithmic scale with respect to the mechanical loading during the experimental procedure. The square of PSC adjusted amplitude PSC(t), expresses an energy quantity [24] and may be calculated according to:     2 PSC i i E t PSC t  where i t corresponds to the time instance of each PSC recorded sample. The cumulative PSC energy PSC CE during each loading is calculated according to the following formula: