PSI - Issue 2_A

M Perl et al. / Procedia Structural Integrity 2 (2016) 3625–3646 M. Perl, and M. Steiner/ Structural Integrity Procedia 00 (2016) 000–000

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Fig. 15. K IA /K 0 vs. ψ along the fronts of crescentic coplanar crack arrays of densities of δ=0, 0.59, 0.8, and 0.89 (a/t=0.4, a/c=0.6, R 0 /R i =1.2, ε =100%).

The influence of crack density in the case of thick vessels is similar. Fig. 16 represents the same crack configuration as in Fig. 14 for a thick vessel of R 0 /R i =1.7. The increase at both the cusp and the deepest point of the crack are practically identical, i.e., ~16%, and ~6% respectively. However, in the case of the thick sphere R 0 /R i =1.7 for the high crack densities of δ=0.81 and 0.89, K IAmax shifts to the cusp, and thus for δ=0.89 it is increased by ~12%, while in a thinner vessel R 0 /R i =1.2 (Fig. 14) K IAmax is only increased by ~6%.

Fig. 16. K IA /K 0 vs. ψ along the fronts of crescentic coplanar crack arrays of densities of δ=0, 0.59, 0.81, and 0.89 (a/t=0.1, a/c=0.6, R 0 /R i =1.7, ε =100%).

4.2.2 Influence of crack ellipticity a/c Figs. 17, 14, and 18 depict the influence of crack ellipticity on K IA /K 0 distributions for coplanar crack arrays of various ellipticities a/c=0.2, 0.6, and 1.0, of crack depth a/t=0.1, and of different densities prevailing in a fully