Issue34

J. Saliba et alii, Frattura ed Integrità Strutturale, 34 (2015) 300-308; DOI: 10.3221/IGF-ESIS.34.32 304 At the peak load, the localization maps show that the AE events appeared first for LN200 beams, then SN200, UN100 and UN200 respectively. The localization maps at 50% in the post peak region show also different crack evolution with a more important crack length for notched beams. For unnotched beams, the localization of AE events begins earlier for UN100 then UN200 with a more important crack length indicating also a more ductile behavior for small beams due to different stress gradient along the ligament length. A crack branching was also observed in the localization maps of UN200 and SN200 which could be due to an aggregate interlock. 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) UN200 Relative notchdepth= 0 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) UN200 Relative notchdepth = 0 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) UN200 Relative notchdepth= 0 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 10 20 30 40 50 60 70 80 90 100 0 50 100 150 200 250 300 Y (mm) X (mm) UN 100 Relative notchdepth= 0 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900aJ 0 10 20 30 40 50 60 70 80 90 100 0 50 100 150 200 250 300 Y (mm) X (mm) UN 100 Relative notchdepth= 0 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 10 20 30 40 50 60 70 80 90 100 0 50 100 150 200 250 300 Y (mm) X (mm) UN 100 Relative notchdepth = 0 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) SN200 Relative notch length =0.2 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) 0‐10aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900aJ SN200 Relative notchdepth= 0.2 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) SN200 Relative notchdepth = 0.2 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) LN200 Relative notch depth = 0.5 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) LN200 Relative notch depth= 0.5 0‐10 aJ 10‐50 aJ 50‐100aJ 100‐300 aJ 300‐900 aJ >900 aJ 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 Y (mm) X (mm) LN200 Relative notchdepth = 0.5 0‐10 aJ 10‐50 aJ 50‐100 aJ 100‐300 aJ 300‐900 aJ >900 aJ Figure 4: Localization maps of the AE events at the peak, at 50% of the maximal strength in the post-peak region and at the end of the rupture test for UN200, UN100, SN200 and LN200 beams. C HARACTERIZATION OF THE FPZ ifferent approaches were proposed to determine the length of the FPZ based on the AE technique. Lertsrisakulrat et al. [20] and Watanabe et al. [21] proposed different simplified empirical relations for the localized compressive fracture length. They considered that the length of the FPZ is equal to the zone where the local energy is superior to 15% of the total energy in the specimens or the region where the distribution of peak amplitude or AE energy is superior to 30% as the AE criterion to distinguish the failure zone. The length and the width of damage D