Issue 46

A. Deliou et alii, Frattura ed Integrità Strutturale, 46 (2018) 306-318; DOI: 10.3221/IGF-ESIS.46.28 314 Figure 11: Diagrams of δ and δ 'with respect to charge P. Figure12: Evolution of the hysterical energy of the crack as a function of ΔK The advantage of this program is to be able to estimate this hysteretic energy for the low values of ΔK. We notice that Q increases when ΔK increases for the three zones studied. Fig. 13 represents the evolution of the specific energy expended U per cycle in function of ΔK in the three zones studied. This energy is given by the following relation [31], [55]: