Issue 35

N. Oudni et alii, Frattura ed Integrità Strutturale, 35 (2016) 278-284; DOI: 10.3221/IGF-ESIS.35.32 283 Figure 5 : Horizontal displacements at the crest of the dam We note that the displacements are relatively low during the first two seconds because of low the amplitudes of the excitations. The displacements reach their maximum at 3.7 s and 7.5 s, 30 mm was recorded at 3.8 s, the maximum displacement value does not correspond to the maximum amplitude of the excitement that is recorded at 3.65 s. The nodal displacements decrease after 7.5 s. Figure 6 : Damage evolution, t D and c D . Fig. 6. Shows the evolution of t D and c D , the tensile and compressive part of the damage variable D . We note that traction damage is more significant and more predominant than in compression, which leads to a brittle fracture of the material by traction. The total rupture of the material can be achieved by traction, in compression the damage is less significant, so the rupture will not occur under compression, Fig. 1b presents some ductility of the material. It is also seen from this figure (Fig. 6) that the tensile damage starts firstly and evolves quickly to a value close to 1 ( 1 t D  ), then followed by the compression damage, but the temporary difference is only of the order of a thousandth of a second, so nearly or completely insignificant difference. In counterparty, compressive damage is less important, it increases until a value 0.15 c D  a value that does not allow rupture in compression of the element. Damage were observed (see Fig. 7) in the dam after 3.53 s at the integration point (815) of the element 204, then from 3.54 s at integration point (811) of the element 203 and finally, from 3.54 s at Gauss point (807) of the element 202. It may be noted that the evolution of the damage is mainly concentrated in the time interval where the maximum values of positive and negative displacements occur.