PSI - Issue 52

Valerio Acanfora et al. / Procedia Structural Integrity 52 (2024) 340–347 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Figure 3: Impact force history for models with different number of elements though the thickness.

In order to achieve an even more accurate simulation, it is mandatory to account for the intra-laminar failure that could occur during the impact event. A formulation based on the Hashin criteria for the onset of failure and the associated degradation of material stiffness is adopted to reproduce the intra-laminar damage. Models with four and eight levels of discretization have produced more accurate results, compared to those without intra-laminar damage in terms of impact force, displacement, and artificial energy. Notably, strong oscillations in the contact force history can be observed. The intra-laminar damages are shown in Figure 4.

Figure 4: Intra-laminar damage in the specimen, four elements through thickness.

In Figure 5, the damage dissipation energy and artificial energy are reported as well. It is worth to notice that the artificial energy, related to the hourglass control, must be lower than the 10% of the total energy, which is equal to 10 J, to obtain reliable results.