Issue 16

F. Carta et alii, Frattura ed Integrità Strutturale, 16 (2011) 34-42; DOI : 10.3221/IGF-ESIS.16.04 37 Figure 5 : Representation of the clamping system (on the left) and of the anti-bending device (on the right). The observed crack lengths within the two bays were practically symmetrical: this has permitted to draw the crack propagation curves [ a = f(N) ] considering the average crack length between the left and right crack tip displacement (see Fig. 6). Figure 6 : Experimental FCP curve illustration of left and right crack length and their average values (two bays-cracked panel). N UMERICAL MODELING he panels tested at EADS-IW are simulated using finite element analysis with the commercial software ABAQUS. A quarter of the panel was modeled so as to limit the computational complexity. Two important approximations in the FE analysis are: - the propagation occurs in the perpendicular direction to that of load application (Mode I); - the front of the crack is assumed to be straight and modeled with two elements in the thickness (see Fig. 7). Figure 7 : Straight crack front in the thickness direction. T