PSI - Issue 8

A. Pantano et al. / Procedia Structural Integrity 8 (2018) 517–525 A. Pantano, B. Zuccarello/ Structural Integrity Procedia 00 (2017) 000–000

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mentioned above, is uniquely defined by the ratio a/l (see Fig. 1c) is highlighted. Fig. 2a and 2b show the distribution of fibers along the laminate thickness (direction 3 in Fig. 1a); in particular it is noted that there are, as in the specimens considered in the subsequent experimental tests, two arrays of fibers having the sinusoidal shape offset by π . Fig. 2a shows the three-dimensional view of the upper edge of the model where the ends of the rear fibers are visible, while Fig. 2b shows the three-dimensional view of the sole fibers by making visible the fibers placed on the second lamina. The following Fig. 3a-e show the different models studied for the variation of the fiber curvature, that is, the variation of the ratio a/l (the frontal view of the models was rotated by 90°). In detail, Fig. 3f shows the model with a/l = 0.05 and V f = 0.2 where the matrix was rendered invisible to highlight the distribution of both fiber arrays.

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Fig. 2. Finite element model ( a/l = 0.05, l = 350 mm, w = 50 mm, s = 1 mm, V f = 0.2); (a) three-dimensional view of the upper edge; and (b) three-dimensional view of the sole fibers.

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Fig. 3. Frontal view of finite element models with different fiber a/l ratios ( V f = 0.2). (a) a/l = 0.025, (b) a/l = 0.05, (c) a/l = 0.075, (d) a/l = 0.1, (e) a/l = 0.125, (f) a/l = 0.05 where the matrix was rendered invisible to highlight the distribution of both fiber arrays.

The total reaction force F and the displacement of the top surface of the numerical model were used to extrapolate the stress data σ =F /( sw ) and deformation ε for the different finite elements models and to obtain the elastic modulus E = F/(swε) .