PSI - Issue 28

A.M. Al-Mukhtar / Procedia Structural Integrity 28 (2020) 124–131 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 2. Crack initiation from the notches [35]

2. Simulation method 2.1. Materials and Geometry

The aluminum metal panel, 500 mm x 500 mm was simulated. The plate is axis symmetric. Figure 3 shows the rivet holes in the periphery of the plates. The values of ν, and E were chosen as 0.293 and 68 GPa, respectively. The materials have been assumed to be isotropic, linear elastic. Figure 3 shows one FE mesh with 8-noded, plain strain elements. 2.2. FE Model and Boundary Conditions The Fracture Analysis Code 2-dimensions (Franc2d) is a FE based simulator for curvilinear crack propagation in planer structures (plane stress, plane strain, and axisymmetric). CASCA version 3.2 [36] is used for the creation the meshes (see Fig. 3). It is a preprocessor for generating initial input files for Franc2d. This program has the ability to analyze a cracked body using special isoparametric crack tip elements. Franc2d has been used in different publications and different case studies, see Refs [1][2][14]–[17][28][37]–[41][3][42][4][6][8][9][11]–[13][37]. Franc2d is used for the first time to simulate the cracking from the rivet holes in the fuselage. Boundary conditions through the fixity in x- and y-directions are used as shown in Fig. 3. The distributed loads in the upper and left edges have been used to produce the biaxial loading conditions. During the crack trip, the load distribution is changed to maintain the theory of maximum tangential criteria. The line of holes is distributed around the plate. Franc2D shows that the maximum stress intensities developed when the plane of the crack is normal to the direction of the primary tensile stress. However, as the plane of the crack tilts further away from the mode-I tensile loading, the structural member, in the form of a plate or a similar configuration, will lose its ability to support the external load [9].