PSI - Issue 2_B

Ch. F. Markides et al. / Procedia Structural Integrity 2 (2016) 2881–2888 Ch. F. Markides, E. D. Pasiou and S. K. Kourkoulis / Structural Integrity Procedia 00 (2016) 000 – 000

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Fig. 3. An overview of the numerical model (left) and a detailed view of its central region (right).

Based on the results of Fig.2 it was concluded that a number of about 55200 elements is satisfactory. The final form of the reference model is seen in Fig.3. Concerning the validation of the model it was achieved by considering the limiting case, in which the properties of the two semi-discs and the adhesive layer are identical. The numerical results for the vertical displacements along y-axis were compared against the respective ones obtained experimentally with the aid of Digital Image Correlation for a uniform disc made of PMMA (Kourkoulis et al., 2012). The proximity of the two approaches is satisfactory as it is seen in Fig.4(left). Discrepancies close to the disc-jaws contact arcs (y=±50 mm) are attributed to deviation of PMMA from linearity due to severe stress concentration in these regions. 3. Parametric numerical analysis Before proceeding to the parametric analysis an overview of the displacement field developed in the composite disc is gained by drawing the x-component of the displacement, u x , all over the disc’s area ( right picture of Fig.4). The asymmetry due to the difference of the semi-discs materials especially close to their interface is clearly seen.

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Fig. 4. Validating the model against experimental data obtained using DIC (left). The u x displacement for the reference model (right).