PSI - Issue 24

Alessandro Castriota et al. / Procedia Structural Integrity 24 (2019) 279–288 A. Castriota et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 7. Strain field at the reference load P

The reliability of the numerical model was proven comparing numerical and experimental strain on points where uniaxial strain gages were applied. This comparison was reported in Fig. 8: also in this case strain was normalized using the maximum experimental strain.

(a)

(b)

Fig. 8. Numerical vs experimental: (a) comparison of the normalized deformations for some points of the panel with saw-cut; (b) comparison normalized load – displacement experimental curve and calculation of experimental axial normalized stiffness

Fig. 8b shows the comparison between the numerical and experimental stiffness, which allow calculating a numerical stiffness higher of about 9.28% with respect to the experimental one. This result is however acceptable, considering the ideality of the numerical model.

5.3. Numerical comparison of intact and damaged panels

Once reliability of the numerical model of the damaged panel was confirmed by the comparison with the experimental result, it is possible to perform a comparison between the behavior of intact and damaged panel on a numeric basis only. Therefore, the simulation was carried out with the same assumption on the intact panel in order to determine the deformation field and the buckling load. Fig. 9a shows some deformation values for the panel in the